HELP with power supply for spyrograph

[Kevlar]

Well I finally finished my 4 motor laser spyrograph build. Here are some pics:

I used 4 DC motors 1.5V-3.0V, 4x25 Ohm rheostat pots, 4xDPDT switches (3A rated), and a 50mW green module (2.9V-3.0V)

So I thought I could use this DC adapter to power it:

It provides 1A and I can select how much voltage.

Now the problem. It works with 1 and 2 motors fairly well but powering up a 3rd or 4th motor bogs it right down. It goes dim and even goes out. If I slowly power up the 3rd/4th motor it will go dim but not out. As the motor is gaining RPM's it's dim but once it reaches it's set speed, determined by the pot, it gets brighter again.

I hope all that makes sense.

So, am I not getting enough current?

 

[Coherent Light]

Your power supply cannot support the load. You need a higher current output supply.

 

[anselm]

Is everything wired in parallel from the same source?
Then yeah, probably not enough current.

 

[Flaminpyro]

Have you tryed just powering 3 and 4 only to see if maby there is something not right with them ?
If they work corectly then you need more current you could try moving the selector switch to the next higher voltage and see how that works.

 

[Kevlar]

Your power supply cannot support the load. You need a higher current output supply.

Thank You!!

Is everything wired in parallel from the same source?
Then yeah, probably not enough current.

Yes, and Thanks!!

Have you tryed just powering 3 and 4 only to see if maby there is something not right with them ?
If they work corectly then you need more current you could try moving the selector switch to the next higher voltage and see how that works.

Thanks FP, I did try that as well. Also tried 4.5V but it seemed to make it worse. So more current it is.

So what would be a good current? 2A?

 

[Ash]

Yes, what Coherent said.
Your motors are probably using more than 250mA each. Try a power supply with at least 2A. :beer:

 

[Kevlar]

Yes, what Coherent said.
Your motors are probably using more than 250mA each. Try a power supply with at least 2A. :beer:

Sweet, thanks again everyone. That is an easy fix. But here is another question, What would it take for batteries to power it for around 1 hour?

 

[anselm]

A 18650 or two spring to mind.:thinking:

 

[Cyparagon]

Here's a wild idea. Instead of making several assumptions, measure the draw of each of the components at full power, then make your supply selection.

 

[Kevlar]

Here's a wild idea. Instead of making several assumptions, measure the draw of each of the components at full power, then make your supply selection.

Wow!! Thats nuts!! Kinda crazy alright, but I'll give it a try. :tinfoil:

All sarcasim aside, thanks Cyparagon.

 

[Bluefan]

And don't increase the voltage of the psu to try to get them to work, you may blow up some components when the load is lower.

 

[Kevlar]

So I tried measuring the load on 1 motor at full speed and as soon as I touch the leads to the motor terminals, it makes everything stop. It's like the DMM is putting such a load on the power supply it just shuts down. :thinking:

 

[Meatball]

You're measuring current by breaking the circuit and putting the meter between the broken leads to make it a part of the circuit... right? An ammeter is a very low resistance device.

 

[anselm]

You're putting the DMM set to current mode in parallel to the motor?
You're shorting out the circuit!