DiscoverCircuits.com, has 30,000+ electronic
circuits, cross-referenced
into 500+ categories. We have searched the web to help you
find quick design ideas.
We make every effort to link to material posted by the designer.
Please let us if you would like us to link to or post your
design.
The contents &
graphics of Discovercircuits.com are copyright protected.
LINKING to Dave's circuits is permitted but DO NOT COPY any files to your WEB
SITE server
Charge Coupled
MOSFET Relay
This circuit acts as an AC/DC relay with a rating up to 50 volts peak and
up to 10 amps of current. The differential oscillator supplies
voltage to the gates of the two FETs with good isolation will drawing only
1.5ma of current.
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.
Circuit Protects from
Battery Polarity Reversal
This simple circuit can protect a sensitive electronic circuit from an
accidental connection of a battery with a reversed polarity. The N-channel
FET connects the electronic device to the battery only when the polarity is
correct. The circuit shown was designed for a device powered from a single
1.5 volts button cell battery. However, the circuit will operate with
higher voltages as well.
FINGER TOUCH ACTIVATED
SWITCH
It does not get any easier if you want a solid-state switch that is activated by
the touch of a finger. Two small metal pins route voltage through the finger
skin to a MOSFET switch. The circuit is great for situations where a membrane
type mechanical switch is not desired.
