In this post I have explained a simple yet very useful 0 to 50V dual power supply circuit which will enable a full 0 to maximum dual voltage +/- control of the input power supply DC. It also includes a wide range current control feature right from 0 to 10 amps. The idea was requested […]
Newly Updated Circuit Projects:
GSR Sensor Circuit for Biofeedback Measurements
In this post I have explained how to build a very simple GSR sensor circuit using just a couple of transistors and a few other passive components. A GSR (Galvanic Skin Resistance) sensor, also known as a skin conductance or electrodermal activity sensor, measures the electrical conductance of the skin, which changes in response to […]
Op amp IC 741 Datasheet, Pinout, Applications
The 741 is a popular general-purpose operational amplifier (op-amp) IC that was introduced by Fairchild Semiconductor in 1968. It has since become one of the most widely used op-amp ICs in the world, due to its versatility and low cost. Below is a typical datasheet for the IC 741: General Specifications: Pinout Configuration: The pinout […]
BC547 Transistor Datasheet [45V, 100mA NPN Transistor]
BC547 is a 100 V, 200 mA, NPN transistors, which is a general purpose small signal transistor. The following paragraphs discuses the datasheet of BC547 transistor for a quick reference. Pinout Configuration The following diagrams shows the pinout configuration and the symbol of the transistor BC547: Absolute Maximum Ratings: Electrical Characteristics: Equivalents 2N2222: Another typical […]
Breath Detector Circuit
The breath detector circuit I have explained below can be used to check or monitor the breathing function of a human or patient. So I have explained the detailed working of the circuit from the following explanation: Component Functions LM324 Op amp: A few operational amplifiers (op-amps) in the circuit magnify the minute voltage changes […]
Bicycle Dynamo Battery Charger Circuit
In this post I have explained a simple constant current bicycle dynamo battery charger circuit which can be used for charging a Li-Ion or Ni-Cd battery from a bicycle dynamo electricity source. The idea was requested by Mr. Saif Khan. Technical Specifications I want to charge a battery through a dynamo fitted to a cycle. […]





