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 […]
Discrete-Circuits
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 […]
Relay Driver – Electromagnetic
This circuit is a standard way of driving Small Power Relays from Control Signals generated by Logic or Opamp Circuits. C2 and R5 form a […]