Tiny visual zero beat indicator

This circuit is suitable for an indicator to audio signal lower than 3Vp-p. In the circuit, we use a very small parts with only two of the LED display and built-up resistor for current depression. Light-emitting diodes(LED) connected with reverse polarity provide a visual indication of zero-beat frequency. Each Led… Read more »

The stray magnetic fields meter.

Electronic technology is common. Although it has much useful. But it is a kind of environmental pollution. Which is called “Electomog” or we will called Stray Magnetic fields (SMFs). And, Some experts said that “SMFs” has effect to the human body. The SMFs that is referenced in this project will… Read more »

Electronic Thermometer with versatile control.

Technology does not stand still. This electronic thermometer that display by LED 20 level and The peripheral Bells Alarms. When the temperature reaches the preset value. On a daily basis. We have to work a lot. If someone would have noticed and remind us always. To the dangers of heat… Read more »

Cheap frequency meter by CA3130

The electronics are still used to use a frequency generator circuit beuause It is important. And are used a lot in electronic circuits, both sine, square wave and more. In every time related to the frequency. What that we want to know is how much frequency. For laboratory common standards…. Read more »

The cheap digital voltmeter using CA3162 and CA3161

This digital voltmeter circuit is a saving, easy to use Because it is smaller than a typical circuit, I believe that, after I presented this circuit. You will certainly like it. This circuit can be used as Versatile. Features of the circuit : – 3-digit numeric display with LED 7… Read more »

Simple three step level indicator

Today we look at the concept of a simple level indicator circuit, which are built to be very small, can be displayed with LED 3 step. When see in the below circuit is very simple. We use a variable resistor(Potentiometer) with 3 unit only, making this the circuit cheap and… Read more »