Recording control circuit for visitor interphone

Abstract

The invention discloses a recording control circuit for a visitor interphone. The recording control circuit comprises an electret Y, a capacitor C1, a potentiometer RP1, a triode VT1, an operational amplifier U1 and a key switch SB. One end of the electret Y is connected with one end of the capacitor C1 and the potentiometer RP1. The other end of the potentiometer RP1 is connected with the other end of the electret Y and the other end of the capacitor C1 and is grounded. A slide sheet of the potentiometer RP1 is connected with a capacitor C2. The other end of the capacitor C2 is connected witha resistor R1 and a base of the triode VT1. A collector of the triode VT1 is connected with the other end of the resistor R1, a capacitor C4 and a resistor R2. The circuit provided by the invention is built in the visitor interphone; through matching of a recorder, when a host is not at home, a visitor recording function can be realized; after the host gets home, who visits today can be timely known by the host; for a visitor without urgency, an owner can know a visit record without paying communication fee; the owner is informed of the visit unobtrusively; and the practicability is high.

Description

technical field [0001] The invention relates to a control circuit, in particular to a recording control circuit for visitor walkie-talkies. Background technique [0002] With the advancement of urbanization in the country, people in cities are living in communities. The existing high-end communities pay special attention to the safety of the community, and have added various access control functions, such as visitor walkie-talkies, which can realize direct communication between visitors and owners, and allow owners to recognize Many visitors enter the community, but there are many times when the visitor comes suddenly and the owner is not at home. At this time, the visitor may need to take out the mobile phone to send a short message to the owner or call the owner. On the one hand, the communication cost is increased. On the other hand, , It is not very convenient for visitors. After all, sometimes there is nothing to worry about. It is not very appropriate to call the owner...

AI Technical Summary

Problems solved by technology

[0002] With the advancement of urbanization in the country, people in cities are living in communities. The existing high-end communities pay special attention to the safety of the community, and have added various access control functions, such as visitor walkie-talkies, which can realize direct communication between visitors and owners, and allow owners to recognize Many visitors enter the community, but there are many times when the visitor comes suddenly and the owner is not at home. At this time, the visitor may need to take out the mobile phone to send a short message to the owner or call the owner. On the one hand, the communication cost is increased. On the other hand, , it is not very convenient for visitors. After all, sometimes there is nothing to worry about. It is not very suitable to call the owner to tell the owner that he has visited before. It seems very embarrassing

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