Undervoltage delay release circuit a

The undervoltage release works for a long time. When the power supply
voltage drops within the operating voltage range, the release is released and
directly drives the tripping half shaft to rotate, causing the circuit breaker to open.
    There are two types of undervoltage tripping devices: instantaneous tripping and delayed tripping
. There are two ways to achieve under-voltage delay trip
: one is an electronic release (see Figure 6-81); the other
is a resistance-capacitance delay release, the circuit of which is as shown in Figure 6-84
shown. In the figure, Q is the undervoltage release coil. The delay time can be changed
    by adjusting the parameter values ​​of capacitor C and resistors Ri and R2
.