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Component selection
The crystal diodes in the circuit are all NPN type silicon tubes except BG2 is a PNP type manifold. The penetration current of these diodes should be chosen as small as possible, and the B value should not be too small, and can be used at around 50. Speaker specifications are: 8 ohms, 0.4 watts, 2 inches. The light-emitting diode LED has an illuminating current of about 5 mA. Photoelectric tube D1 is model 3DU33, and can also be replaced by other types of photodiodes. The motor M is modified with a commercially available DC toy motor with a working voltage of 1.5 to 3 volts:
Delay relay is a kind of Signal Relay classification, is commonly used in automatic control system devices, generally used to connect and disconnect the circuit, is an important component of automatic control and remote control circuit.
Delay Relay,Delay Relay Module,Industrial Time Delay Relays,Signal Delay Relays
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