Current going to load is controlled by Simple Current Limiting Circuit using ICs LM317/LM338. These chips also work as current limiters if set properly. Power comes in as Vin. LM317/LM338 have 3 pins: input, output and adjust. Vin goes to input pin. Output pin (Vout) goes to load and gives limited current. Circuit Working: Parts […]
Air Flow Detection Circuit
Air Flow Detection Circuit means basic electric circuit to check if air is moving or not. People use this in machines or home projects to watch air flow. In this project we make very simple circuit to see if air is moving. We used broken AC bulb and few cheap parts to feel air. This […]
Simple Laser Diode Driver Circuit using IC LM317
One way to give steady current to laser diode is using a Simple Laser Diode Driver Circuit using IC LM317. Laser diode are very sensitive to current and with wrong current can damage it. LM317 usually gives voltage but here it gives constant current instead. Circuit Working: Parts List: Category Item Quantity Resistors 330Ω 1/4 […]
Light Detector Circuit using Wheatstone Bridge
LDR change resistance when light fall on it. This is used in Light Detector Circuit using Wheatstone Bridge. One side of bridge has LDR and one fixed resistor in series. Other side has potentiometer and second fixed resistor in series. Voltage is given to two opposite corners of bridge. The output voltage taken from other […]
Frequency Divider Circuit
A Frequency Divider Circuit take signal with high frequency and give signal with lower frequency. It changes the signal in way to reduce frequency. Two common ICs used for this: IC 4017 Decade Counter: IC 555 Timer: Circuit Working: Parts List: Category Item Quantity Resistors (All resistors are 1/4 watt unless specified) 10k 1 47k […]
Two-Way Intercom Circuit
This simple Two-Way Intercom Circuit let two places talk to each other like old home or office system. Main parts of this circuit are: Microphone: change voice to electric signal Audio amplifier (LM386): make mic signal strong Speaker: change strong signal back to sound SPDT switch: choose talk or listen mode Battery: give power to […]