Ward Caller Five

Published:2011/8/12 1:43:00 Author:Felicity | Keyword: Ward Caller | From:SeekIC

Work of the circuit The circuit consists of power circuit, triggers control circuit and the acousto-optic call circuit. (It is showed in picture 9-88.) Power circuit consists of fuse FU, power transformer T, rectifier diode VD, filter capacitor Cl, limiting resistor R7 and zener diode VS. Triggers control circuit consists of Sl-S3 (ward bedside switch), resistors Rl-R6 and light HLl-H calendar and relay Kl-K3. The acousto-optic call circuit consists of light HU-HLg, KI-K3 normally open contact, capacitor C2, music integrated circuit IC, transistor V, and the speaker BL. This ward caller consists of power supply circuit ,trigger-control circuit and acousto-optic calling circuit. When S1-S3 are not pressed, HL1-HL9 are all off and BL is noiseless. When one of S1-S3 is pressed, the relay in this branch closes, and the indicator is on. At the same time IC is power on and the music electrical signal output by O/P is amplified by V to drive BL to send out music sound. For example while S2 is pressed, HL3 and HL4 is on. Then K2 closes, and the normally open contacts K2-1 and K2-2 are switched on to make HL8A on, and BL sends out music sound.



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