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# Need of simple circuit that can turn transistor on for 10 sec and turn off for 10 sec PLEASE HELP!!

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#### Dzoro

##### New Member
Hi guys i am planing a project to power a dc motor on for 10 seconds in one direction and 10 seconds in other direction and repeat the proces over and over.
For reversing the direction i have an idea to make it with xor logic gate but first I need a simple circuit that can turn a transistor on and stay on for 10 seconds than turn of the transistor and stay turned off for 10 seconds and so on please help
I was thinking of a 555 timer or a mosfet with capacitor that can discharge but i need your suggestion on what should i make.
The input voltage can be from 5 to 12 volts.

I would really apreciate your support.

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Hello. You might find this useful:

LTSpice is also available and is professional level and free. It is not difficult to use but it does take more effort than the one I linked above and might be overwhelming if you're brand, brand new.

Good, go for it. Lots of knowledgeable people here (not so much myself...)
Post questions. You will usually get mostly good answers, some alternatives, and a few incorrect answers. Part of learning...

.

MC14060 or CD4060 is a 14 stage counter and oscillator.
Check my math.
Ctc=0.01uf, Rtc =100k, Rs in the 220k to 900k range. Adjust the value of Rtc to get the right frequency.
Q14 output should be at about the right frequency. I would drive a relay that reverses the motor.

What are the voltage and current ratings for the motor? Depending on the numbers, this might be doable with two CMOS 555's and no external transistors.

ak

I am thankful for the replays but i know an idea how to controll the motors forward and backwards but what i don't have is a schematic that can just turn on and off the transistor nothing more

MC14060 or CD4060 is a 14 stage counter and oscillator.
Check my math.
Ctc=0.01uf, Rtc =100k, Rs in the 220k to 900k range. Adjust the value of Rtc to get the right frequency.
Q14 output should be at about the right frequency. I would drive a relay that reverses the motor.
View attachment 116393
View attachment 116394
I like the idea and i think i have that counter in my workbench but can you be more specific and send me a schematic with the transistor i sad and the whole conections it will be really helpfull

Build an astable 555 circuit that turns the output on for 10 seconds then off for 10 seconds. Google it or see http://www.ohmslawcalculator.com/555-astable-calculator for circuit and capacitor and resistor values.

Connect the 555 output to the gates of two mosfets, a P-channel and an N-channel. See **broken link removed** and search for "Complementary MOSFET Motor Controller" (last topic on the page), although as noted there could be a problem at the moment of switching if both mosfets conduct at the same time.

MC14060 or CD4060 is a 14 stage counter and oscillator.
Check my math.
Ctc=0.01uf, Rtc =100k, Rs in the 220k to 900k range. Adjust the value of Rtc to get the right frequency.
Q14 output should be at about the right frequency. I would drive a relay that reverses the motor.
View attachment 116393
View attachment 116394
So i find the datasheet of the ic and i see what to do i need 2 resistors in series from pin 11 to pin 10 and a capacitor from the rtc resistor to pin 9 and i will hook up an led to maintain the duticycle and i will put a potentiometer ob rtc

Build an astable 555 circuit that turns the output on for 10 seconds then off for 10 seconds. Google it or see http://www.ohmslawcalculator.com/555-astable-calculator for circuit and capacitor and resistor values.

Connect the 555 output to the gates of two mosfets, a P-channel and an N-channel. See **broken link removed** and search for "Complementary MOSFET Motor Controller" (last topic on the page), although as noted there could be a problem at the moment of switching if both mosfets conduct at the same time.
wow thats realy helpful thankyou this is the simplest method so far for the switching part
But for the mosfets can you be more specific

When the 555 output is high the N-channel mosfet turns on. When the output is low the P-channel mosfet turns on.

If you check that Mosfet page I referred to however you will see that at the moment the circuit switches it is possible that both mosfets will be on for an instant, releasing the magic smoke.

What you may need is a little H-bridge motor driver chip instead of the mosfets. Google it.

When the 555 output is high the N-channel mosfet turns on. When the output is low the P-channel mosfet turns on.

If you check that Mosfet page I referred to however you will see that at the moment the circuit switches it is possible that both mosfets will be on for an instant, releasing the magic smoke.

What you may need is a little H-bridge motor driver chip instead of the mosfets. Google it.
Ooo so you think when let say the n chanel mosfet turns on the motor spin clockwise and when the p chanel mosfet turns on the motor spins counterclocwise

Correct. Or you could use the 555 and a double pole double throw relay. See

Ooo so you think when let say the n chanel mosfet turns on the motor spin clockwise and when the p chanel mosfet turns on the motor spins counterclocwise
I was thinking of h bridge but i don't whant to spend too much money beacose as you say i could see the magic smoke and if that keeps happening that's a waste of money and mosfets in my country aren't cheap

Correct. Or you could use the 555 and a double pole double throw relay. See
I was thinking of using an xor gate at the output of the timer
Input a is going to be always high and when input b is high also at the output of the logic is low and when the output is low on the timer the output of the logic is high i think you get how i want it to drive the motor beacose i dont want any clicking noise by the relays

By the way i have a lot of parts i don't need to order and if i order some they will arive one or two months later and i can't wait that long .
And that thing with the relay was realy helpfull for some other projects

I hope your motor is a low power one. High power motors don't like to be instantly reversed, as that creates high mechanical and electrical stresses.

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