Using this electronic circuit can be built a simple warning circuit for lights (something like at car lights). Anode of diode D1 is connected between the switch and light bulbs. The cathode is connected to 12V buzzer. The other terminal of the buzzer is connected to one of the doors or the terminal 31B contacts the cable lights indoors. When one contact is open while the lights are on outside of the car, buzzer begins to sound.
Power diode D1 can be small, such as 1N4001, but D2 must be of higher current, such as 1N5401.
Using electronic circuit below can be made an electronic switch for halogen lamps. Switching circuit, for low voltage halogen lamps, extends the life of these lamps as they provide increase slowly filament current.
Lamp switch T1, a MOSFET channel resistance which is only 0.08 ohms, providing low loss (<250 mW, where the prototype). Control is via modulation pulses in duration, which also tends to minimize losses.
Using SLB0586A integrated circuit manufactured by Siemens is possible to build a simple dimming circuit with touch control. Used with a triac type TIC206D, it enables smooth adjustment of light intensity data from 10-400W bulb. Requires a coil of 100 uH / 5 A to suppress switching noise.
Sync pulses are created from network voltage with R11, C4 and D4, and applied to pin 4 of the circuit.