En power blinker der er anvendelig i alarmer, advarselsudstyr, bilulykke blink, signaludstyr med mere. Der benyttes en power transistor til at drive lampen, og et styringskredsløb til at frembringe de nødvendige impulser til at tænde og slukke lampen. Kan håndtere 12V lamper op til 20W. F.eks. autolamper. How it Works The circuit can be divided in two parts. The first part is a built around the integrated circuit HEF4001 which is a CMOS IC, and contains four NOR gates. Two of the gates (N1 and N2) form an astable multivibrator which oscillates at a frequency of approximately 1 Hz. The other two gates are connected in parallel and their function is to buffer the multivibrator's output and isolate it from the load. The second part of the circuit uses three transistors which are controlled by the oscillator and switch the lamps ON and OFF. The first transistor Q3 amplifies the signal of the oscillator and drives the output transistors which are connected in a DARLINGTON PAIR configuration to improve their power handling capacity. The circuit as you can see is continuously connected to the supply. When the switch is closed and the load is connected to the circuit's output the capacitor C3, which up to this moment was charged, is rapidly discharged through D1 and the load. The pin no 13 of the gate N1 goes high and this forces its output (pin 11) to go low. This forces the outputs of N3 and 4 to go high and this immediately turns Q3 and, consequently, the DARLINGTON PAIR on. The multivibrator starts oscillating at a frequency of approximately 1 Hz and the lamps flash with the same frequency.