DC motor controller circuit

This is a DC motor controller circuit, built using transistor TIP31 based on H-Bridge concept. The switch S1 and S2 are normally open , push to close, press button switches. The LED function is to indicate the direction of motor rotation, you may use any common LED type. The TIP31 Read more…


1.3W RF Amplifier Circuit

This diagram is a schematic diagram of RF amplifier circuit. The circuit will amplify the RF signal about 10 times, 100mW input power to 1.3W output power. It use a general NPN RF transistor 2SC1970. You may apply other transistors, for example 2N442. Circuit Diagram: Circuit Works: RF system and Read more…


5v regulated solar cell power supply circuit diagram

Powered with solar panel, the circuit will give you 5V pure regulated DC voltage. This solar cell power supply circuit is made up of an oscillator transistor as well as a regulator transistor. The solar panel charges the battery when sunlight is bright enough to generate a voltage above 1.9v. Read more…


Simple Metal Detector Circuit Diagram

This is a very easy build, simple metal detector circuit, built based on a CS209A IC. The circuit will give surprising results and draws extremely small current from a 9 volt battery. It worked great on the bench, but not so good outside for common metal detecting. But definately a Read more…


easy build motocycle alarm

The following circuit is a simple, cheap and easy build motorcycle alarm. The circuit just required 2 transistors to drive the relay the the relay act as a switch to activate the buzzer. Any number of normally-open switches may possibly be applied. Fit the mercury switches to ensure that they Read more…


Electro-harmonix graphic equalizer circuit

This is the diagram od electro-harmonix graphic equalizer. You can specify the number of channels according to your needs. You just need to parallel the components: C1, C2, R1, an om-amp, Potensiometer and a 470 ohm resistor. The frequency to be boost decided by C1, C2 and R1. See the Read more…


three rails regulated power supply

This circuit generates 3 source regulated voltages applying a minimum of electronic parts. The output DC voltage are +12V ; +5V and -5V. Diodes D2 and D3 conduct full-wave rectification, at the same time charging capacitor C2 on each halves of the alternating current cycle. At the same time, diode Read more…


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