Winding Transformers and Coils
i would need your help in designing transformers for rechargeable lamps. i really don’t understand what the dots in front a coil stands for. all help (including pictures) would be really appreciated. my own...
Author: delabs
NE612 – Balanced mixer with Local Oscillator
I am designing a circuit that implements an AM radio circuit that ultilises the IC Double mixer and Oscillator NE612. I was just wondering whether there is any standard symbol for this kind of...
Resistance Measurement Analog LED Meter
This is a LED Analog Meter, This can be used as a Resistance Meter and Low Impedance Voltmeter for Battery Levels. To measure battery voltage, the R5-R12-R17 etc. part of the Reference Resistor Divider...
LM555 Voltage Doubler
This circuit shows the voltage doubler working with a 555. LM555 has good drive 200mA, both Vcc and Gnd. 555 has the advantage of having a high drive as well as being a Mixed...
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...
BCD Thumbwheel to Voltage Interface
This is a Proportional Controller where the setpoint is derived from a Thumbwheel switch. The conversion of Thumb-wheel Digital Data to Analog mV is similar to R-2R Weighted Resistor Network. In this case it...
Battery Backup for SRAM or Microcontroller
This circuit can be used as a low cost SRAM and Microcontroller or Microprocessor Battery Backup. All the diodes are 1N4148, The diodes prevent battery discharge back to power source. D8 gives a one...
Audio Visual User Interface with Ack
This circuit is an User Interface part of a Security Alertness Monitor that i designed decades ago. The circuits are here – Digital Circuits – Part 1 The RAM and RTC part is missing, i will add later....
