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DiscoverCircuits.com -- Hobby Corner
Last Updated on:
Tuesday, June 01, 2021 03:06 PM
Hobby Circuits List
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LINK to Dave's circuit, but DO NOT COPY any files to your WEB
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Lamp / Light Control Circuits
Switch Circuits Control Circuits |
Pushbutton Controlled Up/Down
Ramping Light |
There are times when you want a lamp to gradually change from dark to light and from
light to dark, with each push of a pushbutton switch. The circuit below
performs this control function using a flip/flop and a classic pulse width
modulation or PWM method. The circuit uses a common flip/flop IC to control
the on and off logic states. A simple pushbutton switch toggles between the two
states with each press of the button. A 555 timer is used to generate a
triangle waveform clock while a common voltage comparator produces the PWM signal.
An n-channel FET switches power to the lamp with up to 3.5 Amps of current.
This power switching device can be sized as needed, so it could control much higher
current if needed. The circuit will operate from 6v to 15v. With the component
values shown, the lamp will slew from dark to light in about two seconds. This
time can be lengthened or shortened by changing the value of the 1uF capacitor.
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Click on Circuit Below to view PDF of Schematic |
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