Driver stage for switching load for motor vehicle door control

• Main Author: MURR, ROBERT
• Format: Patent
• Language: English; German
• Published: 14.09.2000
• Edition: 7
• Subjects: BASIC ELECTRONIC CIRCUITRY; ELECTRICITY; PULSE TECHNIQUE

The driver stage has a series circuit of a load (L), a switching transistor (Q1) and resistor (R1) between operating voltage poles. The switching transistor is switchable with control signals by a driver transistor (Q4) whose emitter is connected to ground pole and whose collector is connected to the plus pole via a sixth resistor (R6) and via a fifth resistor (R5) to the switching transistor's base. The emitter of a short circuit transistor (Q2) is connected to the plus pole, its collector to the switching transistor's base and its base via a second resistor to the switching transistor's emitter. The switching path of a parallel transistor (Q3) controllable in synchronism with the switching transistor is connected to the short circuit transistor's base and via a third resistor to the switching transistor's collector'. Die Emitter-Kollektor-Strecke eines Schalttransistors Q1 einer Treiberstufe wird durch Einschalten eines Kurzschlußtransistors Q2 bei größer werdendem Laststrom hochohmiger und Laststrom und Verlustleistung des Schalttransisitors dadurch geringer. Dieser Effekt wird durch Parallelschalten eines Spannungsteilers zur Emitter-Kollektor-Strecke des Schalttransisitors mittels eines Paralleltransisitors Q3 verstärkt.