Transistorized Bar-Graph Driver
A resistor network (Rl through RIO) with emitter followers (Ql and Q2) drives LED drivers (Q3 through Q7). ...
Wheel Of Fortune
This circuit is a 10-LED spinning wheel that "clicks" as the wheel passes each point. The rotation starts fast, then gradu...
Flashing Led Controller
The LED with integrated flasher is connected in series with the base-emitter junction of transistor Tl. Thus, the l...
Xenon Flasher
Using a voltage-doubler supply, this circuit charges a 60-/aF capacitor and discharges it through a Xenon lamp. The SIDAC dev...
Pseudorandom Simulated Flicker Sequencer
The pseudorandom sequencer drives a solid-state relay. If you power a low-wattage lamp from the re...
Flip-Flop Independent Lamp Driver
Assume first that SCR1 is on and SCR2 is off so that CI is fully charged, with its LMP2 end positive. The...
Common-cathode-led-display
Here, a Teledyne TSC7135 DVM chip is used to drive a multiplexed 5-digit display. A CD4513BE CMOS IC, for common cathode drive, is used as a segment driver sel...
Variable-strobe-light
In this strobe-light, two circuits are needed; one circuit charges a capacitor placing 320 V de between the cathode and anode of the flashtube. The other circu...
Power-consumption-limiter
A simple solenoid driver uses incandescent lamp filaments as on-indicators to limit power consumption. High magnetic reluctance (opposition to flux) in the c...
Electronic-photoflash
Using the CA3164A BiMOS control chip consumes less than 15 pA during standby, yet it can provide 100 mA of chopped current to the de-to-de converter during the...
Line-operated-power-outage-light
This circuit provides emergency lighting during a power outage. The phototransistor should be positioned to maximize coupling of both neon light and ambient li...
Indicator-lamp-driver
A simple solid-state relay circuit drives the 10-Vac telephone indicator lamps from logic circuitry, ...
Led-peakmeter
The ·circuit includes a peak detector that irrunediately drives the readout to any new higher signal level and slowly lowers it after the signal drops to ze...
Warning-light-and-marker-light
A flashing light of high brightness and short duty cycle is often desired to provide maximum visibility and battery life. This necessitates using an output tra...
Lighted-display-brightness-control
This circuit provides a very low cost method of controlling light levels. Circuit power is obtained from a relatively high source impedance transformer or moto...
Light-controlled-lamp-switch
A school drama needed lamps that automatically turned on and off when spot lights did the same. Lamp switching had to be wireless, durable, dependable, simple ...
Constant-brightness-control
An automatic control maintains a lamp at a constant brightness over a wide range of supply voltages. This circuit utilizes the consistency of photodiode respon...
Pulse-width-lamp-brightness-controller
At half brightness, the lamp current is pulsed on and off (Fig. 50-12b) by the voltage developed across the resistor and capacitor at the current-sense output....
Line-voltage-automatic-night-light
This circuit has stable threshold characteristics from its dependence on the-photo diode current in the Ll4Cl to generate a base emitter voltage drop across th...
Solid-state-light-dissolver
The dimming action is controlled by varying the amount of current passed through triac Q4 and, thus, the lamp plugged into ac receptacle SOL Unijunction transi...