IIRC, the 4017 can be forced into, "dot" mode. One output fires at a time. To get them to sequence, you apply a ramp wave or a sawtooth wave at the input of the 4017 chip. It will go through selecting each output, one at a time, as the input voltage changes.

You are thinking of an LM3914 bar graph display.

 

Darn! Missed again.

A 4017 is a 15 volt, divide by ten counter.

 

Can you describe how you tested your coils? Was it perhaps by direct connection to a power supply?

Your circuit is the right idea and is exactly how I would do it, but the 4017 outputs need to be amplified with external transistors. A transistor array which contains multiple transistors in one package might be a handy option. See ULN2803 or ULN2003.

The way i tested the coil i connected it to my modified circuit with a darlington pair of bc108c transistors

 

Hmmm... Those are 200mA rated transistors, so it's still a mystery how much current was actually in the coil when you judged them to be adequate. Something other than the coil may have been limiting the current.

Without more details - power supply voltage, coil ohms or winding details, mA of current in your test - it's tough to offer much advice. Shooting in the dark.

 

Two questions:
Is he really trying to power this with a 9 volt battery?

What is the resistance of the coils (he has a DVM)?

 

the 4017 counter has no buffeers on the outputs. one output with a low resistance load could stop the count. you need to have buffers (transistors probably) to handle the current of the coils and to isolate the outputs from the loads.

 

the 4017 counter has no buffeers on the outputs. one output with a low resistance load could stop the count. you need to have buffers (transistors probably) to handle the current of the coils and to isolate the outputs from the loads.

He said that he used the darlington pair of bc108c transistors to drive the coils in #43.

 

There should at a minimum be a decoupling capacitor across the '4017, but maybe more to the point, does VDD change much when you connect the coils?

 

There should be a 10k resistor between the 4017 output and the transistor base. Less than that may cause problems.

Also, you will need to have a diode in reverse bias across the coil to take care of the back EMF when the transistor turns off, or the transistor (and maybe the 4017 too) will be destroyed.

 

There should be a 10k resistor between the 4017 output and the transistor base. Less than that may cause problems.

Also, you will need to have a diode in reverse bias across the coil to take care of the back EMF when the transistor turns off, or the transistor (and maybe the 4017 too) will be destroyed.

Hi what do you mean by reverse bias as i have one end of the coil coming from the 4017 through the darlington pair and into the coil and the other side is connected to the positive line is this done correct?

 

Also i tried to put a diode across the coil legs and nothing changed . . .

 

I should've posted a schematic; sorry about that. Here you go:

 

If you've tried running it without the diode, you have probably already destroyed the 4017 and/or the transistor.

 

There should at a minimum be a decoupling capacitor across the '4017, but maybe more to the point, does VDD change much when you connect the coils?

I will check and do my best as i am not with my circuit at present but from what i have seen the coil holds the current from the rest of the circuit.

 

If you've tried running it without the diode, you have probably already destroyed the 4017 and/or the transistor.

how do i know if the 4017 is destroyed?

 

Does it start cycling again if you disconnect the coil? If so, then your coil's resistance is too low for your power supply, and the 4017 is probably OK then.

 

Does it start cycling again if you disconnect the coil? If so, then your coil's resistance is too low for your power supply, and the 4017 is probably OK then.

Hi and thank you for your reply. And yes the circuit carries on once the coil is taken out.
( sorry for the long reply i'm babysitting)

 

Does anyone know the circuit for a stator with 7 outputs please?

 

Maybe a stator circuit would be more suited i'm not sure

 

Does it start cycling again if you disconnect the coil? If so, then your coil's resistance is too low for your power supply, and the 4017 is probably OK then.

is there such things as a 7 phase stator?