800W-soft-start-light-dimmer
The zener provides a constant voltage of 20 V to unijunction transistor Ql, except at the end of each half-cycle of the input when the line voltage drops to ze...
Lamp-life-extender
Lamp life can be extended by improving the conditions under which its filament is operated. This includes eliminating the inrush overcurrent surge and reducl...
Light-modulator
The lights seem to dance in time with the music. Line-voltage lamps of about 40 to 100 W do nicely. The current for the lamp is from an SCR. When low-level a...
Pseudorandom-sequencer
This pseudorandom sequencer drives a solid-state relay. If you power a low-wattage lamp from the relay, the lamp will appear to flicker like a candle"s flame i...
Halogen-lamp-dimmer
This circuit is suitable for fitting into slide projectors without a dimmer facility as witb 24-Vac fed halogen lamps. With a few small alterations, it can als...
Visual-level-indicator
This indicator is basically a switch with hysteresis characteristics. If the input voltage momentarily (or permanently) exceeds the most positive reference leve...
Lamp-flasher
The circuit is built around two power FETs, which are configured as a simple astable multivibrator to alternately switch the two lamps on and off. The rc val...
Minimum-component-flasher
Opening SA, changes the indicator lamp from flashing to steady-lit condition. The 6-V incandescent lamp on the collector of Q2 requires about 0.3 A. A 1-KO l...
Transistor-flasher
This astable multivibrator uses incandescent lamps in place of collector load resistors. ...
60W-flashing-light
The 2N6101 transistor should be mounted on a small heatsink. The 300-KO resistor controls tbe off period and might need to be adjusted if transistor gains ar...
Cmos-flasher
Uses a low cost CMOS IC to tum four LEDs on and off at a rate that is set by the values of R1, R2, Cl, and C2. The pulse rate for the component values given fo...
Scrchaser
Each lamp lights in succession to give the appearance ...
Single-lamp-flasher
The flash rate is controlled by a complementary multivibrator ...
Ac-flasher
is capable of flashing a large lamp. Flashing rate is determined by the 10-KO resistor and the 50-mF capacitor. ...
Scr-ring-counter
One lamp at a time is lit in the string to give the appearance of a moving point of light. ...
Ring-around-led-flasher
When power is first turned on, two of the LEDs are on and the other two remain off until the timing cycle reverses. The LEDs flash in pairs, but by pressing an...
Fiber-optic-led-driver
The pull-up transistor of the totem-pole output is used-to turn on the LED and the pull-down transistor is used to turn ·off the LED. The lower impedance an...
Two-variable-led-matrix-display
This matrix can show the values of two variables, for example, frequency and voltage. The display is a graph made from a matrix of LEDs. The LEDs on each axis ...
Audio-controlled lamp
This is an on-off control with isolated, low voltage input. Since the switching action is very rapid, compared with the response time of the lamp and the respon...
Sound-modulated light source
This circuit modulates a light beam with voice or music from the output of an amplifier. If the 10 K pot is adjusted to slightly less than the Vbe of the transi...