A well-known IC LM35 is chosen to be the temperature sensor in this circuit. Output voltage of LM35 will increase by 10mV per degree rise in temperature. Output of LM35 is joined to the non inverting input of the operational amplifier (op-amp) of CA3130. The inverting input of the same op-amp could be provided using the required reference voltage using variable resistor R2.
This is the scheme diagram of automatic 9V battery charger circuit, the parts list provided below the schematic image. The circuit was designed by Jan Hamer, translated by Tony Van Roon dan republished in this circuit diagram site. The circuit details are based on european standards: 120E, 150E, etc. The ‘E’ just stands for Ohms… Read More »
This is the LED pilot light (or LED indicator) circuit. LEDs (Light Emitting Diode) part are interesting things. They only operate at DC supply within specific tolerances, and generally connected with a current limiting resistor towards the power source. Rather than a resistor, it is possible to use a FET (Field Effect Transistor) like the… Read More »
Here is the circuit diagram of lantern dimmer / flasher designed by Tony Van Roon: There are two circuit modes: dimming and flashing. The flasher mode is useful for warning other drivers of your troubles and it may be adjusted to have a very short flash duration for long-term use as when the car must… Read More »
Here the simple mic pre-amp circuit design based on single IC LM358. The circuit is very simple, inexpensive and easy to built. This mic pre-amplifier circuit operated with 9V DC voltage, you may use 9V battery for this circuit. Component Parts List: R1, R3, R4 = 10K R2 = 1K R5 = 100K-1M Potensiometer C1… Read More »
This is a A/B Box switch pedal schematic with two inputs and one output and featured with dual operational amplifier modules. This circuit was designed by Rick Barker. This A/B Box effect was originally designed for switching between different harmonica mics. This A/B Box featured low noise dual preamp for better performance.
The following circuit is an distortion booster effect for your electric guitar. I don’t know whether this circuit is really works or not, you may try this circuit with your own risk. The circuit is very simple with required only ten electronic components : two transistors, two diodes, five resistors and two capacitors. Supply voltage… Read More »
The following scheme diagram is the battery charger circuit for 6V Gel Cell battery type only. Components List: R1 = 22 ohm, 1W R2 = 270 ohm R3 = 220 ohm *R4 = 715 ohm, 1% *R5 = 3.57K, 1% *R6 = 1.40K, 1% *R7 = 1.47K, 1% C1 = 0.1uF, ceramic C2 = 0.1uF,… Read More »
The following diagram is the schematic diagram of 12V NiCAD battery charger with charging rate of 200mA/Hour. Components List: Resistor: 1 K Ohm, 68 Ohm, 2 K Ohm, Potensiometer 10K Ohm Diode: IN4001, 2x Zener IN752 Transistor: 2N2219, 2N2222