Microbuzzer.com · Posted on 18-05-2009 by microbuzzer

This is used in the lift button on a circuit through the hardware circuit to achieve the buzzer background about the driver as follows:

1. Due to the limited space available in the circuit can only choose SMD passive buzzer  (original height-saving considerations, the high active), which implies the need for oscillation circuit, he can work.

2. Button for calls outside the lift up and down arrow button panel, in the same board, the working principle of the button press the button when it was the signal to be input to elevator control system, control system to determine if the response is the key output a signal to the button’s lamp lights (signal lights in the elevator to the floor running when the control system and then to clear) If you do not respond to the buttons do not light the lamp.

3 customers now take into account the blind use of buzzer signals the need to add, that is, when the blind by pressing one button, the control system when the output light signal, this time the work needs to trigger buzzer,click (about 200ms), but if a second time to the blind, he could not see the lights, I do not know has been in accordance with button-off, so even if a key has been registered, press the button this time, if at this time, you also need to buzzer about to tell the second button are registered blind. However, if the control cabinet is not pressing the button does not respond to their light output signal, at this time press the button buzzer is not loud.

4. Two buttons (the upper and lower) utility of a buzzer

To sum up the circuit is divided into two parts, the logic part of the button and buzzer driving circuit part

1. Button logic include the following signals, the key signal S1, the button lights L1, the next key signal S2, the next button lights L2, buzzer control signal Q

L1 relatively high priority, when a signal is triggered when the rising edge of the ring buzzer, when the L1 in the high when the signal S1 If the button is pressed when the rising edge, but also trigger buzzer, S2 L2 found in the group with the same conditions in the above will trigger buzzer, as the buzzer sound is only 200ms, a relatively short time, the competition between the two sets of button does not consider the time being.

2 buzzer driver, as part of the output of a logic level signal or trigger signal when the output of the circuit’s frequency of 200 ms square-wave signal of 2700HZ.

3. Due to button the signal is relatively simple power supply circuit board does not provide voltage conversion for 24V, in order to achieve these functions, please use the cheapest way to build circuits. Please expert guidance, did not say clearly, please point out the places.

Tags: , , ,
Posted in TECHNOLOGY | Comments (0)