Selasa, 31 Agustus 2010

Rangkaian ON OFF Sleep Timer Switch

ON/OFF Sleep Timer Switch

This timer was designed mainly to switch off a portable radio after some time: in this way, one can fall asleep on the sand or on a hammock, resting assured that the receiver will switch off automatically after some time, saving battery costs.

Rangkaian ON OFF Sleep Timer SwitchSkema Rangkaian ON OFF Sleep Timer Switch

R1 and C1 provide a very long time constant. When P2 is momentarily closed, C1 discharges and the near zero voltage at its positive lead is applied to the high impedance inputs of the four gates of IC1 wired in parallel. The four paralleled gate outputs of the IC go therefore to the high state and the battery voltage is available at Q1 Emitter. When P2 is released, C1 starts charging slowly through R1 and when the voltage at its positive lead has reached about half the battery voltage, the IC gate outputs fall to zero, stopping Q1. This transistor can directly drive a portable radio receiver or different devices drawing a current up to about 250mA. Connecting a Relay across the Emitter of Q1 and negative ground, devices requiring much higher voltage and current operation can be driven through its contacts.

Pushing on P2 for 1 to 5 seconds, the circuit starts and then will switch off after about 35 minutes. This time delay can be varied by changing R1 and/or C1 values. P1 will stop the timer if required. LED D1 is optional and can be useful to signal relay operation when the load is placed far from the timer.

List Component
  • R1: 10M 1/4W Resistor
  • R2: 4K7 1/4W Resistor
  • R3: 1K 1/4W Resistor
  • C1: 220µF/ 25V Electrolytic capacitor
  • D1: LED
  • D2: 1N4148
  • IC1: 4011 Quad 2 Input NAND Gate CMos IC
  • Q1: BC337
  • P1,P2: SPST Pushbuttons
  • RL1: 12V Relay

Senin, 30 Agustus 2010

Skema Dancing LEDs, Following the Rhythm of Music

Dancing LEDs

The basic circuit illuminates up to ten LEDs in sequence, following the rhythm of music or speech picked-up by a small microphone. The expanded version can drive up to ten strips, formed by up to five LEDs each, at 9V supply.

Rangkaian Dancing LEDsSkema Rangkaian Dancing LEDs

IC1A amplifies about 100 times the audio signal picked-up by the microphone and drives IC1B acting as peak-voltage detector. Its output peaks are synchronous with the peaks of the input signal and clock IC2, a ring decade counter capable of driving up to ten LEDs in sequence.
An additional circuit allows the driving of up to ten strips, made up by five LEDs each (max.), at 9V supply. It is formed by a 10mA constant current source (Q1 & Q2) common to all LED strips and by a switching transistor (Q3), driving a strip obtained from 2 to 5 series-connected LEDs. Therefore one transistor and its Base resistor are required to drive each of the strips used.

List Component of Dancing LEDs Circuit
  • R1: 10K 1/4W Resistor
  • R2,R3: 47K 1/4W Resistors
  • R4: 1K 1/4W Resistor
  • R5,R6,R7: 100K 1/4W Resistors
  • R8: 820R 1/4W Resistor
  • C1,C3: 100nF/63V Ceramic or Polyester Capacitors
  • C2: 10µF/50V Electrolytic Capacitor
  • C4: 330nF/63V Polyester Capacitor
  • C5: 100µF/25V Electrolytic Capacitor
  • D1: 1N4148
  • D2-D11: LEDs (any type and color)
  • IC1: LM358
  • IC2: 4017
  • M1: electret microphone
  • SW1: SPST Switch
  • B1: 9V PP3 Battery
Additional circuit parts:
  • R9,R10: 10K 1/4W Resistors
  • R11: 56R 1/4W Resistor
  • D12,D13 etc.: LEDs (any type and color)
  • Q1,Q2: BC327
  • Q3: BC337
  • The sensitivity of the circuit can be varied changing R4 value.
  • C4 value can be varied from 220 to 470nF in order to change the circuit speed-response to music peaks.
  • Adopting the additional circuit, only one item for R10, R11, Q1 and Q2 is required to drive up to ten LED strips. On the contrary, one item of R9 and Q3 is necessary to drive each of the strips you decided to use.
  • Each R9 input must be connected to IC2 output pins, in place of the LEDs D2-D11 shown. R8 must also be omitted.
  • Whishing to use a lower number of LEDs or LED strips, pin #15 of IC2 must be disconnected from ground and connected to the first unused output pin.
  • For example: if you decided to use 5 LEDs, pin #15 of IC2 must be connected to pin #1; if you decided to use 8 LEDs, pin #15 of IC2 must be connected to pin #9 etc.
  • Current drawing of the circuit is about 10mA.
  • Whishing to use a wall-plug adapter instead of a 9V battery, you can supply the circuit at 12V, allowing the use of up to 6 LEDs per strip, or at 15V, allowing the use of up to 7 LEDs per strip.

Slow journey home

Slowdown interview the Journey Home's creator.

Sabtu, 28 Agustus 2010

Down and Over

CaptainD reviews Over the Edge

Interview Part 12: Ocean-spirited away

Tonight, we host DDQ, famous for being the man behind Oceanspirit Dennis, a craze of some people that just couldn't stay at puns. I present you the interview and a link at the end for the next OCEANSPIRIT GAME IN THE MOST EPIC SAGA EVER MADE.

If you ask what is Oceanspirit Dennis, then damn you, look here.

1) What is your favorite AGS game to the date? And what's your favorite non-AGS game? (You may list more than one)

My favorite AGS game has got to be The Marionette. While it isn't necessarily perfect, the game is incredibly well-written and features an engaging story that personally has no competition. That's probably the best "experience" I've ever had with an AGS game. Honorable mention goes to Shifter's Box. Best one of late is definitely The Journey Down: Over The Edge. You should really be playing it right now instead of reading this.

For non-AGS games, I have a power trio. Paper Mario: Thousand Year Door, Half-Life 2, and the Mass Effect series. While the games themselves are widely different, all feature universes that completely immerse me whenever I play them.

2) What in the name of holy saint does ddq means? And what kind of a quote is "F%$^ the hypotenuse"? How did you come up with each of those?

Ah yes... that's something I've lost many nights of sleep asking myself. I actually created the name while naming my save file for Need for Speed: Underground 2 by randomly smacking the Gamecube controller and ddq5 emerged. I've kind of dropped the 5 since then. As for any meaning, the only thing I know for sure is that the first 'd' stands for "Drew," my name, and the second stands for "Dennis," my favorite name. The 'q' could mean anything, but imagine it's along the lines of "quality," "quadratic," or "quadriplegic."

"F%$^ the hypotenuse" is a phrase that my brain conjured up from the ether. When I first thought of it, I thought it would be the kind of thing you'd see on an xkcd t-shirt. It might also be related to the TV Tropes page "Murder the Hypotenuse," which deals with love triangles. Either way, I just find it catchy.

3) How did you find AGS? Who are the forumites that dragged you in ?

My friend and I were looking to develop an incredibly ill-conceived idea for a game. I looked around the tubes and stumbled upon Adventure Game Studio and thought it looked fancy. One failed game attempt later, here I am.

This was right about the time that a little fellow named Calin Leafshade had posted an audio file of himself reading emo poetry. Pretty soon, I had found myself entering the community during the flurry of activity that surrounded McCarthy Chronicles. But in general, I'd say the whole community was pretty nice for not treating me like the overeager little dips^&t with a bad game idea that I was one year ago.

4) Who is the real Drew? And how much did Igor Hardy paid you to join his awful blog?

Haha. Well, I'll start by saying Igor's an awesome guy and I love working with him. I won't that you should shut up and his blog could kick your blog's ass any day because that would be rude.

The real Drew is studying electrical engineering and computer science at university and enjoys good films, games, and music. He plays the drums and still enjoys Lunchables. He also just got a new desk for free and he really likes it.

5) How did you come up with Oceanspirit Dennis?

Ooh, this is a good one. The concept for OSD was conceived by several people. In our good friend and comrade iceygames' thread on RPGs, he showed a design for his JRPG protagonist, "Dave." I told him Dave was a stupid name for a Final Fantasy protagonist, you know how they are, and suggested something like Ocean, or Spirit, or Dennis. The first two being parodies and the third being my aforementioned favorite name.

Snake then marvelously suggested the combination "Oceanspirit Dennis," to which I appended "Scourge of the Underworld." Then I spent five minutes to this drawing, which I released to widespread acclaim. Then the illustrious Ben304 actually adapted it to a game and others soon followed. Thus was set in motion the wonderful world of OSD.

6) How do you feel about creating the idea for a bunch of games based on a mocking of a troll? Some people even called it a RON revival! Comment on that.

Oceanspirit Dennis had a quick but significant boom of games in the month after Ben released the first one, but it died down pretty quickly. I'm literally days away from releasing the next chapter in the OSD saga but who knows if it will catch on? If so, I think we'd need a common set of sprites and sounds and such, walkcyles and all that. While I think so far all OSD games have been released open source, they've all had wildly different styles.

Still, that allows game makers much more creativity with their designs. Whatever happens with it happens, I guess.

7) So you created another OSD, why? Wasn't there enough? Was this one has to offer?

Well, of the 5 or so games released, the one I did was by far the worst. It was just a so-called "Special Edition" of Ben's original game with voices and added homosexual themes. Also, while some of the OSD games were intentionally stupid as parody, I thought I'd enjoy seeing where I could go with a semi-serious comedy game in the universe. That's why I started Blades of Passion: An Oceanspirit Dennis Adventure. It's really more of an exercise than anything else. It'll be my first real game and I experimented a lot in creating it. Thankfully, I was able to round up a really great team who wanted to continue the OSD saga as well. Plus, Blades of Passion has a sex mini-game.

8) So when are we going to see that game?

Monday August 30th, 2010. The promised is kept here.

Minggu, 22 Agustus 2010

Free to be miserable

Mr Tolworthy has release Les Miserables for free!

Rangkaian LED 220VAC Sebagai Lampu Penerangan

The LED has advantages over other lighting technology. LED supposedly can hold up to 100,000 hours. This means that if the LED light 24 hours a day he would hold for 10 years. Whereas Fluorencent lights are usually only able to survive 1-3 years.

This is a modified version of the circuit, Super bright LED Night Light published that can directly connect to the netting PLN (220VAC).

rangkaian LED 220VACSkema rangkaian LED 220VAC

rangkaian LED 220VAC
Dangerous...!! this circuit directly connected to the netting of electricity, voltage 220V electricity it could sting you. Avoid working in damp and directly with ground

This is the circuit of a well tried and reliable 230-volt AC mains operated 24 LEDs (super bright LEDs 50mA). While Practically compare the brightness Between this and 11watts tube circuit, the LED light is much better. The layout is made in such a way, you get uniform Illumination. A photographs of the cicuit is Also given in this post.

Richard Hofmeier's Cart Life

And to think I was playing Jackyard yesterday, wondering where is Richard's game. Well, here it is, in a Trailer: Cart Life from INDIEGAMESBLOG. Click here to watch.

Kamis, 19 Agustus 2010

Rangkaian Speaker Protector sederhana

Speaker Protector sederhana

This circuit follows will connects the speakers to the power amplifier output only a few seconds after the amplifier is powered ON, so that the speakers do not accept popped up by a high voltage and you would not Hear a loud thud sound from the speakers When the amplifier is switched on. This stuff is very harmful to the speakers.

Rangkaian Speaker Protector sederhanaSkema rangkaian speaker protector

When the amplifier is powered on the bridge D1 also gets powered through the amplifier’s power switch. Capacitor C1 filters the output of bridge rectifier D1. When the power switch is made ON, the transistor Q1 gets switched ON only after the capacitor C2 is sufficiently charged (0.7V) through the resistor R1. Here the value of C2 and R1 are so selected that the time delay is around 2 seconds. So the relay gets activated only after a few seconds the amplifier is powered ON and until that time the speaker will be kept isolated from the amplifier’s audio output as the speaker is connected to the amplifier’s output through the N/O contact of the relay. During this initial delay period the output of amplifier will be grounded by the resistor R2 through the N/C contact of the relay. This is done in order to ensure that the DC blocking capacitor at the amplifier’s output is charged before it is connected to the speaker.

Rangkaian Speaker Protector sederhanaBetter quality speaker protector Circuit

Don't Stop Believing

Well, Journey is one of my favorite bands and Indie Games Blog's favorite freeware pick is the Journey Down. You can read all about it here.

Rabu, 18 Agustus 2010


As the famous racist mysogynist once said in Braveheart, you can take our Release Candidates, but you can never take our freedom. And Pumaman has not taken freedom but given it to AGS 3.2... its now the official current version!

Minggu, 15 Agustus 2010

Rangkaian Magnetic proximity sensors

Here is the circuit diagram of a magnetic proximity switch sensor which can be used in various applications. The circuit is based on a magnetic reed switch as the proximity sensor. A monostable multivibrator based on NE555 and a toggle flip flop CD4013 does the rest of the circuit.

rangkaian magnetic proximity sensors  Skema rangkaian magnetic proximity sensors
magnetic reed switch magnetic reed switch sensor

The magnetic proximity switch sensor circuit, in principle, consists of a reed switch at its heart. When a magnet is brought in the vicinity of the reed switch it operates and controls the rest of the switching circuit. In place of the reed switch, one may, as well, use a general-purpose electromagnetic reed relay as the sensor, if required. These tiny reed relays are easily available as they are widely used in telecom products. The reed switch or relay to be used with this circuit should be the normally open type.

When a magnet is brought in the vicinity of the sensor element for a moment, the contacts of the reed switch close to trigger timer IC1 wired in monostable mode. As a consequence its output at pin 3 goes high for a short duration and supplies clock to the clock input (pin 3 CD4013). LED D2 is used as a response indicator.

This CMOS IC2 consists of two independent flip-flops though here only one is used. Note that the flip-flop is wired in toggle mode with data input (pin 5) connected to the Q (pin 2) output. On receipt of clock pulse, the Q output changes from low to high state and due to this the relay driver transistor T1 gets forward-biased. As a result the relay RL1 is energised.

Sabtu, 14 Agustus 2010

Down with AGS!

So, the traditional annual site and forum downtime is happening... always seems to be at Mittens time...

Jumat, 13 Agustus 2010

Rangkaian Audio Channel Selector Stereo

Audio Channel Selector

This circuit serves for connecting the stereo outputs from Four Different channels as inputs and only one of Them is selected to the output at any one time.

When the circuit switch on, channel A (AR and AL) is selected. If no audio is present in channel A, the circuit Waits for Some time and then Selects the next channel (channel B). This search operation continues Until it detects an audio signal in one of the channels. The inter-channel delay time or the wait Can be adjusted with the help of preset VR1. If still longer time is needed, May replace one capacitor C1 with of higher value.

To manually skip over from one active channel to another active channel, simply push the skip switch (S1), until the desired channel input gets selected. The selected channel (A, B, C, or D) is indicated by the glowing of corresponding LED (LED11, 12, 13, or 14 ).

Rangkaian Audio Channel Selector  Stereo  Skema rangkaian audio channel selector stereo

IC CD4066 contains 4 analog switches, These switches are connected to four separate channels. These analogue switches are controlled by IC CD4017 outputs. CD4017 is a 10-bit ring counter IC. Since only one of its outputs is high at any instant, only one switch will be closed at a time. IC CD4017 is configured as a 4-bit ring counter by connecting the fifth output Q4 (pin 10) to the reset pin. Capacitor C5 in conjunction with resistor R6 forms a power-on-reset circuit for IC2, so that on initial switching on of the power supply, output Q0 (pin 3) is always high . The clock signal to CD4017 is provided by IC1 NE555 which acts as an astable multivibrator when transistor T1 is in cut- off state.

IC5 KA2281 is used here for not only indicating the audio levels of the selected stereo channel, but also for forward biasing transistor T1. As soon as a specific threshold audio level is detected in a selected channel, pin 7 and/or pin 10 of IC5 goes low . This low level is coupled to the base of transistor T1, through diode-resistor combination of D2-R1/D3-R22. As a result, transistor T1 conducts and causes output of IC1 to remain low as long as the selected channel output exceeds the preset audio threshold level.

Presets VR2 and VR3 have been included for adjustment of individual audio threshold levels of left and right stereo channels, as desired. Once the multivibrator action of IC1 is disabled, output of IC2 does not change further. Hence, searching through the channels continues until it receives an audio signal exceeding the preset threshold value. The skip switch S1 is used to skip a channel even if audio is present in the selected channel. The number of channels can be easily extended up to ten, by using additional 4066 ICs.

Dual hits the big time

Adventure Game behemoth AdventureGamers give their opinion on H2G2.

Selasa, 10 Agustus 2010

Interview Part 11: Long Live the Gene - Against All Ods.

And with us we have markbilly, also famous as Mark Richards, creator of the long-awaited Longevity Gene. An interview, I've found very interesting awaits you. May you see it.

1) Do you have a favourite AGS game? Or a non AGS game?

I don't finish many adventure games because I'm rubbish at them, so this should be fairly easy. For AGS it is definitely going to be the Ben and Dan games but I have a particular fondness for Shifter's Box and the most recent Ben Jordan (I was rather late to discover them). As for non-AGS, my favourite adventure is Beneath a Steel Sky and the one title that really solidified my love for gaming was Knights of the Old Republic.

2) How do you feel about releasing your first AGS game ASFAIK (Wall-E) and winning the MAGS as well?

It was a great feeling to actually release a game! I have been sitting on a project for ages, only showing it to a few people and so it was great to 'finish' a project and get some real feedback. Wall-E has a special connection to me anyway, because I originally made it for my girlfriend as a present, so that made sharing it with everyone even better. Winning MAGS was a nice bonus, I was really happy as there were some great games submitted that month.

3) When you first started posting artwork from a game you were working on, that being Longevity Gene, you said you didn't like the graphics, and you felt you needed some help. What really helped you into keeping the project and tutoring yourself?

I had no intention of ditching the project and I suppose the thread was a desperate plea for people to persuade me to carry on. After getting some feedback I went and re-drew a couple of backgrounds and posted them up on the Zombie Cow forum. What I had overlooked was lighting and, after some examples and little tutorial from a couple of the members (CaptainBinky & MashPotato) got that sorted and the rest is history, I suppose.

4) Tell us a bit about the game's production. How it reached here, and where did it actually start from.

Well, this latest version with the updated graphics started just under two years ago. The project is a lot older than that, though. It started off about five years ago as an idea for a text adventure and it had a totally different story. In fact, it has only been called The Longevity Gene for the last two years, before that (as the text adventure) it was called Tractus, which is was crap name frankly. Over those three years it developed into the game you see in this thread and ended up being called Planet 49 and of course later changed to the title I have now.

As for right now, the first part is playable from beginning to end and I'm just going through the stage of adding in all the gaps I left as I went along. Which takes longer than you might think!

5) What length is the game going to be?

The first part is a medium length game. The second part will probably be a little longer. I'm waiting on a secret play tester at the moment actually, so I will have a better idea then.

6) I've had this idea for a long time, but what role did Ben and Dan play in the Longevity Gene? Don't hide it from me, I can scent it.

I've talked about Dan's early role before in an article I did for HardyDev. The game, in its many forms, has always been present on both the Zombie Cow forum and its predecessor the Gibbage forum, both run by Dan and in some part Ben as well. Recently, I have sent builds to Ben and Dan throughout development for feedback. I just trust their judgment, I suppose. They've both always been really kind, even when I was a lot younger and more annoying.

7) Tell us a bit about the members of the Longevity Gene so far.

The cast? Or the crew? I'm not telling you about the cast, sorry! On the crew there is me, Matthew Brown and Peter Faizey. Matthew is doing the sound and Peter does the music. I wrote a little about Matthew in the game's production thread but Peter is one hundred percent not a gamer, so I don't think you'll ever see him on the forum.

8) Who is the real Mark Richards? What is his life like? Hobbies, Jobs, Girlfriends, Plans on taking over the world?

I'm a uni student, barely. I ended up doing a degree that didn't really suit me so I spend most of my time distracting myself. I make films, again with Peter and a couple of other friends. My other hobbies aren't really hobbies, though. I am interested in politics and secular issues and a member of the Labour Party in the UK. Half of my Twitter updates are about politics, actually!

I have a wonderful long term girlfriend, Maria and I work in a supermarket during term, so I think I tick all those boxes!

Oh and I'm building an anti-matter death ray in my garden.

9) What is the main plot of Longevity Gene affected and inspired by (movies, books, tv series, music, novels)

I wanted to make a game after playing Beneath a Steel Sky, so that is a major inspiration and I got my love of choices in games from Knights of the Old Republic. There are a few Blade Runner references in the game and the whole project is in the spirit of classic sci-fi. If I was OK with using unoriginal music in games, I'd definitely have The Great Gig in the Sky as the end credits music.

Rangkaian Kontrol Kecepatan Wiper Mobil

Pengontrol Kecepatan Wiper

For some car wiper speed sometimes just made some speed so that less appropriate when we want a different speed, but for those of you who want a digital wiper speed controller you can also use this circuit to replace your old system.

rangkaian kontrol kecepatan wiper mobilSkema rangkaian kontrol kecepatan wiper mobil

This circuit comprises 2 timer NE555 ICs, one CD4017 decade counter, one TIP32 driver transistor, a 2N3055/ TIP3055 power transistor and A Few other discrete components. Timer IC1 is configured as a mono-stable multivibrator produces a pulse Pls Which one presses switch S1 momentarily. This pulse acts as a clock pulse for the decade counter (IC2) Which advances by one count on Each successive clock pulse or the push of switch S1. Ten presets (VR1 through VR10), for Different sets of values by trial and error, Are Used At The ten outputs of IC2. But since only one output of IC2 is high at a time, only one preset (selected at the output) effectively comes in series with resistors R4 and R5 timing connected in the circuit of timer IC3 Which functions in astable mode. As presets VR1 through VR10 are set for Different values, Different time periods (or frequencies) for astable multivibrator IC3 Can be selected. The output of IC3 is applied to the pnp driver transistor TIP32 for driving the final power transistor 2N3055 Which in turn drives the wiper motor at the selected sweep speed. The power supply for the wiper motor as well as the circuit is tapped from the vehicle s battery Itself. The duration of the monostable multivibrator IC1 is set for a period of nearly one second.

Source :

Senin, 09 Agustus 2010

Masking Tape

Some guy in a mask does a video review of the Blackwell trilogy. Apparently he's called Underdog.

Rangkaian Charge Monitor for 12V battery

This circuit project is a function for monitoring the charge level of 12 volt batteries continuously. The circuit possesses two vital features:
  1. reduces the requirement of human attention by about 85%.
  2. highly accurate and sophisticated methods.
A battery is a vital element of any battery-backed system. In many cases the battery is more expensive than the systems it is backing up. We need to Adopt Hence all practical measures to Conserve battery life.

As per manufacturer's data sheets, a 12V rechargeable battery operated Should be within 10. IV and 13.8V. When the battery charges higher than 13.8V it is said to be overcharged, and it discharges below 10.IV Pls Can it be Deeply discharged. A single event of overcharge or deep discharge Can bring down the charge-holding capacity of a battery by 15 to 20%.

Rangkaian charge monitor for 12V batterySkema rangkaian charge monitor for 12V battery


For calibrating the upper and lower reference levels, a digital multimeter and a variable regulated power supply source are required. For calibrating the lower reference voltage, follow the steps given below:
  • Set the output of power supply source to 10. IV.
  • Connect the power supply source in place of the battery.
  • Now the display will show some reading. At this point vary preset VR2 until the reading on the display just changes from 1 to 0.
  • The higher reference voltage is calibrated similarly by setting the power supply to 13.8V and varying preset VR1 until reading on the display just changes from 8 to 9.

How to Work a Circuit of Charge Monitor for 12V Battery

Input from the battery under test is applied to LM3914 1C. This applied voltage is ranked anywhere between 0 and 10, depending upon its magnitude. The lower reference voltage of 10.IV is ranked '0' and the upper voltage of 13.8V is ranked as '10.' (Outputs 9 and 10 are logically ORed in this circuit.) This calibration of reference voltages is explained above.

1C 74LS147 is a decimal-to-BCD priority encoder which converts the output of LM3914 into its BCD complement. The true BCD is obtained by using the hex inverter 74LS04. This BCD output is displayed as a decimal digit after con version using IC5 (74LS247), which is a BCD-to-seven-segment decoder/driver. The seven-segment LED display (LTS-542) is used because it is easy to read compared to a bar graph or, for that matter, an analogue meter. The charge status of the battery can be quickly calculated from the display. For instance, if the display shows 4, it means that the battery is charged to 40 per cent of its maximum value of 13.8V.

The use of digital principles enables us to employ a buzzer that sounds whenever there is an overcharge or deep discharge, or there is a need to conserve battery charge. A buzzer is wired in the circuit such that it sounds whenever battery-charge falls to ten per cent. At this point it is recommended that unnecessary load be switched off and the remaining charge be conserved for more important purposes.

Another simple combinational logic circuit can also be designed that will sound the buzzer when the display shows 9. Further charging should be stopped at this point in order to pre vent overcharge.