4-220V-test-probe


Posted on Feb 2, 2013

Using inexpensive components, you can fit a simple probe circuit into a pencil-sized enclosure. When both LEDs are on, the probe indicates the presence of an ac voltage; either LED alone indicates the presence and polarity of a de voltage. The diode-bridge arrangement allows one-way current source Rl, R2, Ql, and Q2 to light either LED (or both) when the probe is activated by a test voltage.


4-220V-test-probe
Click here to download the full size of the above Circuit.

Diodes,provide the necessary peak-inverse voltage rating; R3 and Cl provide a spike-suppression network to protect the current-source transistors.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Static Electricity Detector
Two-wire Lamp Flasher
AVR LED RF Field Strength
AM Radio
Multimeter Shunt
Knock Block using an Arduino board
Camera flash circuit
Nikon CLS Slave Flash Trigger
Analog To Digital Converter
Differential Light
Serial programmer circuit for AT89Sx MCUs
NTSC RGB Cable Schematic
Test-Measurement
1490 Digital Compass
Designing Robust and Fault-Tolerant Motion-Control Feedback Systems
Xenon Flasher
INA331 332 configured to directly drive the capacitive input A D converter circuit
Common intermediate frequency amplifier circuit having a circuit and on the radio
Three temperature switch circuits
Using ASCII keyboard code development system



Top