Ohmmeter – Simple Resistance Measurement
Measurement of resistor values in circuit configurations are required to be made often, as these might have changed in value due to various tolerance ranges, […]
Discrete-Circuits
Flashing Mains Neon Lamp
Here is a Neon Flasher circuit (untested) for a user request at Circuits FAQ. This can be built into a switchboard or a gadget for […]
Voltage Doubler with Diodes
This is a Simple Voltage Doubler to boost 3V battery voltage to power some low-power 5V circuits. In needs a Clock input with high fan-out. […]
Simple Water operated relay
This was done in my early days, i have upgraded it, it ought to work, reduce the number of transistors to make it less sensitive, […]
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 […]
Voltage Doublers and Multipliers
Voltage multipliers are used to obtain low current high voltage, from an existing AC Source. Step up transformers can be used, but the insulation problems […]
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 […]
Telephone status indicator with LED
This will monitor telephone status without loading the telephone line, this way if you have two phones in parallel you will know if one of […]