Conrad Course material 3964 14 years and over 3964 Manual De Usuario
Los códigos de productos
3964
13
Fig. 33: A slow alternating flasher (F_Blinker1.jpg)
13.
Step: Simple LED flasher
A flasher unit in a motor vehicle usually activates only one lamp. Another flip-flop is set up here that automatically
switches back and forth. The circuit requires only one capacitor. Two transistors in an emitter circuit form an amplifier.
The feedback from the output to the input passes via a capacitor that repeatedly charges and discharges itself.
switches back and forth. The circuit requires only one capacitor. Two transistors in an emitter circuit form an amplifier.
The feedback from the output to the input passes via a capacitor that repeatedly charges and discharges itself.
Fig. 34: The multivibrator (Schaltung12.jpg)
Fig. 35: The LED flasher (F_Blinker2.jpg)
14.
Step: LED flashing light
This circuit produces regular short flashes of light. As long as the capacitor is still charged, all three transistors remain
blocked. The voltage at the base of the middle transistor increases slowly. At about +0.6 V the middle transistor
begins to conduct and delivers the base current for the PNP transistor. Its collector voltage increases and switches the
LED on. At the same time, the electrolytic capacitor delivers a powerful and brief base pulsed current. The left
transistor in the circuit is for securing the correct operating point of the circuit. About one flash of light per second is
generated.
blocked. The voltage at the base of the middle transistor increases slowly. At about +0.6 V the middle transistor
begins to conduct and delivers the base current for the PNP transistor. Its collector voltage increases and switches the
LED on. At the same time, the electrolytic capacitor delivers a powerful and brief base pulsed current. The left
transistor in the circuit is for securing the correct operating point of the circuit. About one flash of light per second is
generated.
green