Brightness Control for small Lamps


Posted on May 21, 2012

Switch-mode driven 1.5V bulbs. This device was designed on request, to control the light intensity of four filament lamps (i.e. a ring illuminator) powered by two AA or AAA batteries, for close-up pictures with a digital camera. Obviously it can be used in other ways, at anyone`s will. Portable unit - 3V battery supply.


Brightness Control for small Lamps
Click here to download the full size of the above Circuit.

IC1 generates a 150Hz square wave having a variable duty-cycle. When the cursor of P1 is fully rotated towards D1, the output positive pulses appearing at pin 3 of IC1 are very narrow. Bulb LP1, driven by Q1, is off as the voltage across its leads is too




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Preamplifier and high-to-low impedance converter
Beam sputter for oscilloscope
Odd-number-counter-divider
Zener diode tester
video signal amplifier circuit diagram
Precision Receiver Battery Low Voltage Alarms
Electronic Ammeter and Voltmeter
RF Circuitry Links
Computer microphone circuit diagram



Top