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 […]
Thyristor Switching using Snubber Circuit
This article we talk about Thyristor Switching using Snubber Circuit. It is like switch which is used in power electronics for high voltage and current. Thyristor also called SCR (Silicon Controlled Rectifier). It turns ON by gate signal and to turn it OFF the current must stop. But when turning ON and OFF the voltage […]
Long Range IR Transmitter Circuit
Compared to basic circuit this Long Range IR Transmitter Circuit can send IR light farther using easy parts. Main idea is to make IR LED blink light in pulses. Most IR receivers catch specific frequency made by IC 4047. Using more LEDs together or stronger LED gives more IR light, so with better range. This […]