Hotel Room Calling Management System With Digital Display

We are a Manufacturer and Supplier of Hotel Room Calling Management System With Digital Display, operating from India. Hotel Room Calling Management System With Digital Display integrates four ON/OFF switches to indicate the Room Number on respective 7-segment display. The ON switches are arranged in respective rooms. The OFF switches, display and alarm are arranged at control room. When any switch is pressed, the respective number is displayed on 7-segment display. The buzzer sounds an alarm, which alert the controller that someone is calling him. When he is going to attain the room, he can reset the call by pressing OFF switch. If more than one call has made, he can reset all the calls by pressing reset switch. Our valued clients can avail Hotel Room Calling Management System With Digital Display at pocket friendly price.
 
About the Circuit :
The circuit is very simple and easy to use. The associated circuit diagram is shown in figure. It is built around D-Type latch IC74373 (IC1), Hex Inverter IC2 and four 7-segment display driver ICs.
When one presses the ON switch, a logic low is applied to data input D0 (pin3). The same level appears on the data output Q0 (pin 2). Because the latch enable pin LE (pin 11, active high) is connected to +5V and the output enable OE (pin1) active low, is pulled down using resistor R1. At the same time, Q0 output is fed back to D0 input, which thus keeps the common junction of D0 and Q0 at low level, even after releasing ON switch. This low level is applied to one of the hex inverter and high output of inverter is given to 7-segment display driver IC. If S1 is ON, ‘1’ should display on 7-segment display. For that purpose ‘A’ input (pin 5) of display driver IC is connected to output of inverter and other inputs are grounded. Buzzer also raises an alarm until OFF switch is pressed.
When OFF switch is pressed, logic high is applied to junction of D0 and Q0. Because of the feedback from Q0 to D0 junction remains high even after releasing the ON switch. As a result logic low is applied to ‘A’ input and display is reset. The operation is same for other three displays. Only A, B, C, D inputs of respective display drivers are connected to output of respective inverter.