Today I am showing you how to make very powerful pen style electric arc metal engraver circuit using IC 555 and MOSFET. Actually this idea is inspired by one of my blog reader, and my friend Mr. August. He made one crude engraver using 6V transformer and tractor charging coil, but he wanted a smooth […]
Frequency
Extremely Low Frequency (ELF) Radiation Monitor Circuit
ELF stands for Extremely Low Frequency, which is an electromagnetic radiation generated by most of out household electrical equipment. Regarding the effect and severity of ELF fields on human health, debate remains heated. However, I believe there is enough data for us enthusiasts to adopt a conservative stance on the level of exposure we must […]
Tuned Radio Frequency (TRF) Receiver Circuits
A tuned radio frequency receiver (or TRF receiver) is a form of radio receiver which is made using a number of tuned radio frequency (RF) amplifier stages accompanied by a detector (demodulator) circuit to draw out the audio signal, along with an audio frequency amplifier for amplifying the extracted audio into a loudspeaker. This kind […]
5 Digit Frequency Counter Circuit
This digital frequency counter will provide a direct reading of the frequency applied at its input, through a 5 digit common cathode display module. The compact frequency counter can be used for accurately counting the frequency or pulse from any intended source. Main Applications It can be also used for measuring the RPM of a […]
Simple Frequency Meter Circuits – Analogue Designs
The following simple analogue frequency meter circuits can be used for measuring frequencies which may be either sine wave or square wave. The input frequency which is to be measured must be at least 25 mV RMS, for optimal detection and measurement. The design facilitates a relatively wide range of frequency measurement, right from 10 […]
1 Hz to 1 MHz Frequency Reference Generator Circuit Diagram
This circuit is an universal frequency generator which you can use in numerous frequency and time period testing applications. It is primarily well suited for a gate pulse generator in frequency counters. The circuit is capable of generating an entire range of reference frequencies such as 1 Hz, 5 Hz, 10 Hz, 50 Hz, 100 […]





