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AN871 APPLICATION NOTE

Figure 9. "Smart door control" concept based on small triacs to drive each actuator of the various

functions of the front door

Other applications

Small motor breaking. Another example of application of SCR or triac in a DC motor circuit is the dy-

namic breaking. For instance, wipers control requires an accurate positioning when the motor is switched

off.

An efficient solution consists in short circuiting the motor, with the SCR T, as soon the circuit is turned off

(see Figure 10). A MOSFET is also able to break but would cause a short circuit with its body diode in

case of reverse polarity.

Figure 10. Thyristor used in motor breaking

MIRROR FOLDEN

MIRROR

MIRROR

DOOR LOCK

M

M

M

M

M

SUPER

DOOR LOCK

M

VBAT.

DRIVER

T