Home Audio Receiver Deals

I use 9V voltage supply, 5V (via the voltage regulator) water sensor, and then flip-flop (active high), which is connected to DPDT relay, then to the servo motor. When the water sensor on, the motor will rotate in the positive direction, when the water sensor is broken, send multivibrator logic "0" to take over, what will change the polarity of the motor to make it to rotate in the negative direction. The question is how can I make the engine run for some time for both cycles. And also I can get a loan stores electrical multivibrator, because I tried to build it myself, i circuit obtained from the Internet, it didn't work properly. If u have better proposals to implement the task using other components will also be greatly appreciated. Thank you

I suppose you have a motor that pumps water into a tank or cistern. When water falls to a low level, we would like start the engine. Do you want? What is a reversal of the engine? What happens then? If you need to drive for a motor while, you need a timer. This is a device at startup, hold office for a specified period. Thus, you can trigger the device when the water reaches a low level, by detecting the water level sensor. Then, the engine will run for a certain time depending on the time you set in the timer. When the level is lower than min, the sequence repeats. A simple way to obtain a timer is to use a large RC and a driver transistor for the relay. The capacitor at the base can be loaded by a diode, when the trigger occurs, and the capacitor will keep the transistor ON for a while. The transistor can drive the relay. See also the timer based circuits 555.