|
AC Power Control Circuits
Last Updated on:
Friday, April 25, 2008 04:12 PM |
| Circuits Designed by Dave Johnson, P.E. : |
- CHARGE COUPLED BI-DIRECTIONAL POWER MOSFET RELAY
The circuit uses an inexpensive C-MOS inverter package and a few small capacitors to drive two power MOS transistors from a 12v to 15v supply. Since the coupling capacitor values used to drive
the FETs are small, the leakage current from the power line into the control circuit is a tiny 4uA. Only about 1.5mA of DC is needed to turn on and off 400 watts of AC or DC power to a load.
|
|
- SOLID STATE RELAY REQUIRES ONLY 50uA DRIVE CURRENT
This circuit demands a control current that is 100 times smaller than that needed by a typical optically isolated solid state relays. It is ideal for battery-powered
systems. Using a combination of a high current TRIAC and a very sensitive low current SCR, the circuit can control about 600 watts of power to load while providing full isolation and transient
protection.
|
|
| Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:
|
|
Circuit level-shifts ac signals: 07/10/03 EDN Design Ideas (circuit / schematic added 12/04) AC signals can emanate
from many sources, and many of these sources are incompatible with the most popular interface voltages, such as TTL. A temptation always exists to capacitively couple the ac signals because
capacitive coupling strips off the dc level. Capacitive coupling sometimes doesn't work, because the coupled signal's voltage swings around ground, so you have to add dc offset to make...... |
|
Why limit your power supply's input range?: 03/20/03 EDN Design Ideas (electronic circuit added 12/04) Taking only a
cursory look at the input-voltage ratings of your power-supply IC can limit the usable input-voltage range. With careful examination of an IC's operating specifications and circuit topology,
you may be able to work around that input-voltage limitation. For instance, The data sheet for TI's (www....
|
|
|
