Delay light circuit using relay (1)

It is a delay lamp that uses a relay. The characteristic of relay control is that the power capacity of the controlled bulb
is only limited by the relay contacts. Therefore, as long as a relay with a large enough contact capacity is used, the controlled bulb can be
increased of power. Moreover, the controlled electrical appliances are not limited to incandescent light bulbs , but also fluorochrome lamps, electronic energy-saving
lamps and other electrical appliances.
    In the figure, VD,vs,B,R,f1. and C:
form a capacitor step-down half-wave rectification and voltage stabilizing circuit. When
SB is pressed, a DC
voltage of about 12V is output at both ends of Cz. The transistor VT is turned on, and the relay K absorbs the platform and
Gantt is passed until C: IL1 is discharged. To a certain extent, the relay K cannot be kept closed, the electric shock Kl will not trip, and the light
E will go out.
    The role of the small resistor R is enough to reduce the initial allowable current of C to protect the voltage regulator tube vs. vs should use
12V, IW type Zener diode. T has enough freewheeling capacity to make the relay K pull-in more stable and reliable, and at the same time
it is good for extending the delay time. C. It is required to use polypropylene capacitors with a withstand voltage of more than 400v. (1., (1. Can
be used with ordinary (, Dll-16V electrolytic capacitors. K should use JZ (, 121;, DCl?V small electromagnetic relays , and
the contact capacity is very fast oA. Year} |The capacitance is determined by the capacity of the capacitor, which can be
adjusted according to actual needs. At the same time, the length of the key press and the delay time are also affected.