Hi Bill,

Can we stop in the middle of 1sec and continue for 10 sec of next stage? If yes, you can make the new circuit and will change to your sugguestion. I will take whichever is working for my project. Is that to answer your question? Please let me know

Best regards,
Minh

 

Hi Bill,

The TP5 are input from other circuit. If we add 1 second in midle will effective the input? Can you please let me know how to add 1 second without effective the input? and also go revert 10 second as well.

Thanks,
Kevin

 

I have a feeling we are almost communicating, but missing something. I'll lay out another circuit, it will have a 1 second dead time where the motor will have dynamic breaking. It will use a 555 and a 556 (3 timers). I will also add the feature where it will ignore any triggers once the sequence of 3 timers has started.

 

Thanks, Bill. I will wait for your new circuit. You have a nice evening.

Kevin

 

Hi Bill,

I have tried your circuit but not working. I am using relay PN: RT24012 of Typco. I have connected NPN Q3 Collector pin to A1, M1 of motor to relay pin 11 and Q4 collector NPN to Pin A2 of relay, M2 of motor to relay pin 21. The pin 12 and 22 of elay to VCC, pin 1 and 24 are connect to GND. When the output of 556 both M1 and M2 are high, so that Motor not work.

The Q3 and 4 are NPN 3565.

Please let me know what did I connect wrong on the replay?

thanks, so much

Kevin

 

Is the transistor getting hot?

Have you breadboarded this circuit? Can you see Pin 3 switch with a DVM?

 

Yes, I am using breadboard. The pin3 is reset pin connect to GND. I think the Relay not work good for H bridge. Do you know what is the good H bridge IC for Motor 12VDC 4A. I know the Motor is using 4A and 12VDC.

Thanks,

Kevin

 

Hi Bill,

Are you come up for brake 1 second in middle before goes revert?

Thanks,
Kevin

 

Hi Bill,

I am waiting for your third timer, will you let me know? I will check back tonight.

Thanks,
Kevin

 

OK, the top schematic is with the extra timer. The bottom schematic is how you can disable the input while it is sequencing. You might try adding an LED to follow the sequence of timers, since one triggers the next as it is finished for a simple diagnostic. R5 and R6 can be very high resistance, such as 10KΩ, since the reset pin is very high impedance.

The relays are simple, the common contact is simply Vcc or ground, this can be measured with a DVM. You should be able to hear them switch, and if their bodies are clear see it too. When both relays are off both motor power leads are grounded, this will quickly bring the motor to a stop (AKA, dynamic breaking). The relays should be rated for double what the motor is pulling.

C3 may not be necessary, it is to smooth the input to make sure it is continuous. 0.1µF would be adequate.

A couple of reference sheets in my PaintCAD package you might find handy.

http://forum.allaboutcircuits.com/picture.php?albumid=41&pictureid=308
http://forum.allaboutcircuits.com/picture.php?albumid=41&pictureid=977

 

Thanks, Bill so much for your help. I will try it over the weekend and let you know, if it 's working. You have a nice weekend.

Kevin

 

Hi Bill,

The first time I build thirs timer without the CR6 and 7 but When I connect the CR6,7 the 556 has not working any more. May be I connect wrong something? How do I know it brake 1 second? What the value resistor and cap for the new timer?

Best regards,

Kevin

 

Pin 4 must be a logic high (usually power supply). Sound like it is low. If either one of the last two timers is high then reset pin on the first timer will go low.

Try the schematic without CR7 and 8 and see if it works. Pin 4 will be connected directly to Vcc in this case.

 

Thanks, Bill. Since it burn the 556 chip, I need to order new one. I will get back to you once the new part arrive next week.

You have a nice weekend.

Best regards,
Kevin

 

Before connecting relays, try the LEDs and resistors first. It will show the basic action you are looking for before trying it with power.

 

Thanks, Bill. I lucky to get one part left somewhere on my table and tried it working without connect the CR7,8. But the circuit is still goes high by itself and the motor auomatic running once apply the power. Do you have any idea why?

My thanks, to you alot and appreciate your help. Can I have your personal email?

Best regards,

Kevin

 

Hi Bill,

I have removed the Q5 and the motor can brake for 3 second but the second stage goes too long more than 15 second. It should revert 10 second to equal the first stage but it does not. Please let me know why?

Thanks,
Kevin

 

Show me the schematic you are currently using.

 

Hi Bill,

I will draw it and post it tonight.

Thanks,
Kevin

 

Hi Bill,

Here is the drawing. The Relay of second stage sometime go longer than 10 second. The switch of relay is not moving so that keep relay keep high more than 10 second. I had changed the new relay but same result.

Thanks,
Kevin