Principle and circuit diagram of ward calling device

With the development and application of wireless technology, the ward pager system can provide instant communication and mobile reception of call information. Some pagers have been developed and manufactured based on FM wireless technology. It is a system developed by combining single-chip microcomputer and computer technology.

　　Generally, its working principle is as follows: a pager is placed on each bed. When the patient needs service, he only needs to press the button of the pager lightly, and the receiver will display the bed number and send out a music prompt. The medical staff can know the exact bed to be served based on the prompt information and provide corresponding services.

　　Ward caller circuit schematic diagram

　　The following is a circuit diagram of a ward calling device to analyze its circuit principle and circuit design and implementation principle (ward calling system circuit diagram). It is mainly composed of the following three parts: power supply circuit, trigger control circuit and sound and light calling circuit. These three parts are independent and interconnected to complete the function of the whole system. The following is a discussion of the electronic components used in the circuit diagram and the selection of the parameters of the electronic components.

　　A. VD uses 1N5401 silicon rectifier diode;

　　B. C1 uses an aluminum electrolytic capacitor with a withstand voltage of 35V;

　　C and C2 use aluminum electrolytic capacitors with a withstand voltage of 10V;

　　D.VS uses 1/2W, 3V silicon Zener diode;

　　E. R1~R6 are all 2~4W wirewound resistors;

　　F. R7 uses a 1/2W metal film resistor;

　　G. IC uses KD9300 or CW9300 music integrated circuit;

　　H, K1~K3 all use JRX-13 F type 6V DC relay;

　　I. BL uses a 0.25W, 8Ω electrodynamic speaker;

　　J and V use 59013 silicon NPN transistors;

　　K and T use a 5VA power transformer with a secondary voltage of 18V;

　　L, S1~S3 use push button self-locking switch or boat switch;

　　M, HL1~HL6 all use 6.3V, 0.1A red indicator bulb;

　　N, HL7~HL9 use 220V, 10~20W red bulbs;

　　The power supply principle is analyzed as follows:

　　In the circuit, the power supply circuit is composed of fuse FU, power transformer T, rectifier diode VD, filter capacitor C1, current limiting resistor R7 and voltage regulator diode VS; the trigger control circuit is composed of S1~S3 (bedside switch of the ward), resistors R1~R6, indicator lights HL1~HL6 and relays K1~K3; the sound and light call circuit is composed of indicator lights HL7~HL9, normally open contacts of K1-K3, capacitor C2, music integrated circuit IC, transistor V and speaker BL.

　　After the AC 220V voltage is stepped down by T, rectified by VD and filtered by C1, an 18V DC voltage is generated. One path is used as the working power supply of the trigger control circuit; the other path is limited by R7 and stabilized by VS to a 3V DC voltage, which is used as the working power supply of IC. When S1~S3 are not pressed, HL1~Hl9 are not lit and BL does not make a sound. When a switch in S1-S3 is pressed, the relay of this path is energized and the indicator light is on; at the same time, the IC is powered on, and the music electrical signal output from its 0/P terminal is amplified by V, driving BL to make music sound.

　　For example, when S2 is pressed, HL3 and HL4 light up, K2 is energized and closed, and its normally open contacts K2-1 and K2-2 are connected, HL8 lights up, and BL makes music.

　　Functions and features of ward pager

　　A. No wiring required, easy installation and maintenance;

　　B. Improve service response speed to ensure on-call service;

　　C. It can not only solve the bedside call, but also solve the emergency call in the bathroom, activity room, etc.;

　　D. The procedure for patients to call for service is simpler, just press a button;

　　E. Medical staff can carry it with them and provide services in any corner of the venue;

　　F. Communication can be achieved without shouting, creating a good medical environment;

　　G. Reduce labor costs. One medical staff can monitor several wards.

　　H. Reduce management costs, eliminate the need for multi-level human monitoring, improve management efficiency, and save management personnel;

　　I. Two-way calling, dual-function calling, host multi-function display, multi-level care setting, fault self-diagnosis alarm, emergency calling function, etc.

　　How to use the ward pager

　　A. The patient presses the corresponding button of the wireless pager to initiate a call and find a staff member;

　　B. You can know which room or bed is calling and what type of call it is through the LED display host;

　　C. You can get the content of the call through the digital information machine you carry with you, with multiple prompting methods such as vibration and music;

　　D. Install call supervision and management software to query call records;

　　E. Managers can also use wireless dispatch handles or wireless keyboard callers to dispatch service personnel and group call alarms.