Delayed light off, light control chicken called circuit principle

The circuit operation principle of the device is shown in Fig. 4. When the push button switch AN is not depressed, the triode VT is off-biased and turned off. At this time, the c--e-pole resistance of the VT is greater than 50K, so the LSE's 1st and 2nd feet are equivalent to an open circuit, and the LSE's 4th pin outputs a low level. , relay J is released. When the switch AN is turned off, its current is quickly charged to the capacitor C3 through the AN, and the charge is filled in 1 second. At this time, the transistor VT is turned on, and the inter-electrode resistance is reduced, so the LSE is turned on, and the 4-pin output is high. Level, relay J is energized, and lamp H is lit. After releasing the hand, the charge in C3 is discharged to VT through the resistor R, maintaining the conduction of VT. When the charge in C3 is released, VT is cut off, J is automatically released, and H is extinguished. The lighting time of its lamp H depends on the values ​​of R and C3. According to the value shown in Figure *, the delay time is about 1 minute and 30 seconds after the test.

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The circuit operation principle of the device is shown in the following figure. When there is no light shining on the photoresistor RG at night, the internal resistance of RG is very large (far greater than 50K), so the LSE 1 and 2 feet are equivalent to the open circuit, the LSE 4 pin outputs the low level, and the triode VT1 is turned on. Relay J is energized and attracted, its normally closed contact j is disconnected, and the analog chicken circuit IC KD5609 has no power supply and does not work. Once dawn, there is light on the RG, the internal resistance of RG becomes smaller (<50K). At this time, the 4 feet of the LSE output a high level, the transistor VT1 is cut off, the relay J is released, and the contact j is closed, simulating the chicken bark. The circuit is energized to produce a realistic chicken call from the indicator speaker BL.