OR gate with two 555
This shows how to OR gate two 555, when one 555 cycles at a low frequency a valve turns on an off, the second 555 stretches the ON duration of the pulse with a...
Category: Hobby-Circuits
Metal Detector Circuits Problem
With the best wishes for you. I found your address and browsed your website. I have a question and hope to take your help and answer. I need to good metal detector’s circuit and...
What is Saturation in Transistors
Date 8/30/06 Simon and delabs Simon: hello, delabs: hello Simon: we have many meanings for saturation, delabs: means turning on, also means no longer linear, or it is got fixed up, not varying in...
Working with SMD and SMT PCB
One thing tho, i would like to request you to send me some procedures on how to work with surface mount devices (SMD’s). I cant get the IC as DIP so i have no...
FET Current Source and MOSFET
This is a constant current source using a FET. This is the most simple replacement to series resistor to limit current. The N-Channel FET BF256C can give 15mA current. Simple Methods Before you get...
Perpetual Candle – White LED Lamp on Ni-Cd
This is a easy to build LED lamp circuit for Learning and building skills. This is the first draft schematic V 1.0. It will need improvements for Higher Power Lighting. I will give a...
Constant Current Source LED Drive
This is a Constant Current Source LED Driver, When the LED driver Upper-NPN is driven by a voltage thru 4.7K the LED lights up. Assume that the Lower-NPN at bottom is absent. The current...
Digital to Analog with R2R Ladder Network
This is a R-2R Digital to Analog Converter, It converts a byte (8 bit) to a analog value. It has 256 levels including zero. This was the first Digital Pot i Built decades back...
High Resistance Meter
I don’t remember if this circuit worked properly. But a few were made and i might not have shown the modifications that were done to make it work. This was meant to be a...
Musical Sound to Neon Light Flasher
Neon Light Flasher was made by me when i was young, it was even published in a magazine, i think it will work, it was used on a very old huge ornamental valve philips...
Battery Level LED Indicator
This LED Indicator uses a LM339, a quad comparator. LM339 can work on single or dual supplies, it has a open collector output that can drive 15mA, low power consumption. The circuit is an...
Astable Multivibrator with 555 Timer
This is a demo of the popular 555 timer. you can try out the project on this page by a javascript simulation. Press the Red button below to turn on the circuit press it...
