Simple Circuit Diagram


Simple resistive load

Sometimes we need to use a resistors that without capacitance or inductance. We always use the carbon resistors. But some working to need the resistor that has also many high power. Which we cannot use the carbon resistor because it has maximum power about 2 watts only. Normally, performance testing of amplifiers need to apply […]


Noise Filter for Stereo system

In the receiver, stereo radio station. Usually have more noise than listening in mono. Because, the stereo system is splits signals-to-noise ratio. (S/N) There level lower, cause interference, in mono with less. becausePhase noise of the 2-back phase. When combined into a mono signal was decreased by default. As principle the noise is high frequency, […]


Linear opto isolator circuits

This is the linear opto isolator circuits that use a few parts and cheap. In circuit we use the opto compiler ICs number of MOC 5010 as based. It can be used many ways. For example ; separate the circuit from the power line, send audio signal, Electronic medical, etc. How it works The resistance […]


Tape head preamplifier using UPC1032

This pre-tape circuit is cheapest for beginner only. And easy to builds because use one IC-UPC1032 only as Figure 1. Fig1: The circuit diagram This is stereo can connect to the tape header that resistance between 200-600 ohms at output amplitude about 250 mV. Fig 2: The PCB layout The power supply voltage that can […]


Easy Telephone Amplifiers circuit

This is an easy telephone amplifier circuit. It will increase the signal of the telephone lines up. Then, drive the relay to controls the large electric bells that louder than a general phone. This circuit is modified from the speaker protection circuit, so easy and cheap. How it works Figure 1 the circuit diagram. After […]


Analog signal selector switches

Do not waste time, choose the input method with interchangeable input cables. But press the input selector switch, as you like. Easy and cost effective alternative is Input selection switch. With features the optional four-channel signal input. and volume to Increase or decrease the signal. In the event that your power amplifier no volume. How […]



Super Steady Zener diode circuit

This circuit is used for controls the voltage battery is steady, which the zener diode apply very low current about 1mA only, cause there is ripple voltage about 1 mV at voltage changing between 10 to 30 volts. As circuit the output is fixed to 8V. In circuit the reference voltage is connected to input […]


Constant current circuit using LED

Normally the voltage drop across LED while forward bias will be about 1.2 to 1.4 volts depend on type of LED by has the temperature coefficient is -1.5 mV per degree Celsius. Which similar to the temperature coefficient of junction. between a base and emitter of silicon transistors. From this relationship can the constant current […]


Dual DC power using 2 terminal transformer

There are many ways to build the dual power supply from a transformer that has one secondary coil.This good way as Figure 1 use two bridge diodes. The first section is normally working, others section (D1-D4) will work by AC signal from C1 and C2. To filter DC voltage of out others bridge diode of […]