Digital volume control circuit

This is digital volume control circuit that Can be applied to the normal volume of a power amplifier. When press switch S1 adds up the volume and press switch S2 to reduce the volume down.

How it works
IC1 is a 555 CMOS Timer Single IC will be connected in astable flip-flop model as pulse frequency generator up / down to input pin of the counter IC2-74LS193, through push-bottom switch S1 (Up) and S2(Down).


Changing wide of pulse signal from IC1 may replace R1 with potentiometer.

Source: Digital volume control circuit

TV test pattern generator with wireless model

This is a TV test pattern generator with wireless model
The components in assemble circuits not difficult, can transmit signal in wireless are video and audio As horizontal line. Along with tone. Using the power of just one 9V battery.

This circuit is very suitable for TV repairman orThose who want to test that your television ,can use also use it? by it will send video signal in VHF (very high frequency) band. Which is range for use channel 5, 7, 9 and 11. The image appears on the TV screen is a horizontal straight line with Tone out to speaker.

The circuit principle
In Figure 1 is the TV test pattern generator with wireless model will see that is basic astable circuit connected with the modulator circuit there.



Metal detector circuits

Here is a Metal  detector circuit that is simple and cheap. You can use them to find the metal in Ground, in walls, or other. If you are a builder This circuit is very suitable for you.You can detect rebar in concrete or beam. When viewing the details of this project was to create simple, because a very small number of devices.We use NE556 in as base of this project.Within its structures NE555 number 2 PCS. So highly effective, affordable and certainly it can be purchased easily.We also use the meter display. So easy to use and small.You can see the circuit ,PCB layout, and read more….


Simple metal detector circuits

Electronic circuit kits

Today I want to introduce many electronic circuit Kits.Because I understand that sometimes you’re looking for a good electronic project easy creation and effective look below.

Cricket voice with buzzer using LM324

This is a cricket voice circuit which is an another Sound effects generator byLM324 op-amp and emit by a buzzer. And they have sound similarly the crickets are singing a couple we’ve ever heard. In circuit we don’t use any microcontroller ICs so you can build easily them and also cheaper. Technical information – Use power supply of 9 Vdc. – Maximum consumption current about 30 mA – PCB size : 2.25 x 1.57 in …

The 4 sound effect using UM3561

Here is a 4 sound effect that use one IC-UM3561 and a few parts only. It can make siren, Ambulance sirens, Police car sirens, Fire truck siren and Space Machine Gun Sound effect How it does works As Figure 1 is the circuit diagram. To begin with R1 is connected to pin 7 and pin 8 of IC1. Which are the OSC1 and OSC2 pins will controls frequency of the oscillator circuit inside IC1. If value of R1 lower will …

AM simplify radio with earphone

This AM simplify radio with earphone is a saving version that use a few parts, cheap , easy to build and Suitable to be assembled to study. Technical information Use power supply of 3 Vdc. Maximum consumption current about 45 mA PCB size : 2.38 x 1.24 inch. How does it work. A circuit diagram that shown in Figure 1 IC1 MK484 acts as receiver system by have variable capacitor and OSC coil as frequency adjust …

High power 6 LED Flashlight for 1.5V AA battery.

This circuit look like a torch by use on 1.5V battery only so it can be used. Since small so Easy to carry in various places. And also very bright as well. The technical information Power supply : one 1.5V AA battery. Maximum current used 200mA Uses 6 white LED. Small size PCB. How it works As usual, the LED light when voltage is 1.8V or 2V, We need a way to increase the voltage to rise,by the switching sup …

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Automatic ni-cd/ni-mh battery charger

If you need a Nicd and Ni-MH battery charger that automatic cuts off. Which is simple circuit, this project is good ways. It use IC-AN4558 OP-AMP IC. Detection of battery voltage when the power is full. And would be cut off immediately. It is a simple project And budget. How does it works. We are reviewing and understanding a ni-cad battery. Someone may not know it. They have body same a general battery. Bu …

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