Electric blanket, rice cooker timing circuit a

 (l) Introduction to circuit principle Figure 3-30 shows the electric blanket and rice cooker timing circuit. The circuit timing time is ls-lOh or more. In the picture
. cl is the timing component. After turning on the power, press switch ANl, C. Charge until the voltage reaches DC 28V. Comparator A outputs high level and
transistor VT is turned on. When relay J is energized, it will self-lock when ER-1 closes the power supply. Jl-2 is disconnected. C. Discharge to the high-resistance input terminal. When the Cl voltage
drops below the inverting input terminal of A, A outputs a low level, the transistor Vr is cut off, J is de-energized and released, and the timer ends, waiting for the second
time to trigger the switch AN1. Take it.
    (2) Component parameter selection The selection of components is shown in Figure 3-30, and there are no special requirements.
    (3) The electric blanket and rice cooker timing circuit is shown in Figure 3-30.