I have old welder and my wire feed motor circuit stopped working- so i powered up the motor with 24 volt transformer and 24 volt DC motor speed controler ALL works good as it should except when i let off the switch on the mig gun- the wire keeps moveing about an extra 3 or 4" – i thought it was my new transformer so i taped the mig handle switch full on, and then i unpluged the wire rite on the motor so i know no power bleed ing through to the motor-- and then i see the motor still rolls even with no power hooked up to the motor-- so i have come to the conclusion the the welder wire feed power supply must have a stall circuit or a reverse timed brake ciruit to keep wire feed motor from rolling after power is unhooked.---------------------------- ANY BODY know ANYTHIG about a stall circuit type motor speed control --or transformer 110 -220 ac too DC 24 volt-- WITH MOTOR STALL CIRCUIT. IF THEY ARE ON EBAY OR AMIZON I NEED ONE- or what they are called. THANKS
Hi Kevin, wire feed motors can be wired various ways, some have separate wiring for the field magnets, and the armature, through brushes, this to be able to control/brake the motor.
Simplest way use to be, when letting go of the trigger, a relay disconects the motor from the variable power supply, another shorts the motor, connects the + and - together, letting the motor act as a generator which is shorted. This effectively stops the motor from turning free.
Windshield wiper motors use to be wired this way to, to get the blades to “park” nicely.
THANKS GORAN K-
for the knolwledge on the short circuit brake–as far as unpluging power to the motor that dont seem to work-roller keep moving about 2 more inches or so depending on how fast motor was turning when unpluged- so thats why i say there must be a sort of brake built into the welder wire feed motor circuits- Could you add some sort of timed short circuit unit between my 24 volt pwm and the motor- or is there a pwm that has that short circuit function built in.
Something like this may work, on a 2 pole motor, easy to wire, single shifting relay.
When trigger is pulled relay shifts to B
In “rest” it shorts the motor A.
I know some welding equipment has a timer circuit to be able to adjust after-feed, to avoid wire " burning up" stuck in nozzle.
Maybe there are shifting relays with built-in timer, i have on in a curcuit in my truck, shifting, 10-30 volt, made by Hella i believe, but i dont know if it’s sensitive enough, i use it with a delay of 20 seconds, to much for a welder, lot’s of wire spools at that time
THANKS again GORAN-K that sounds too simple- VERY-NICE drawing of what it looks like .would you happen to know a link to a 24 volt type single shift solinoid.?
OK i will head out too shop and loose the 2 wire nuts on motor wires and see if it works with out any othe volt addjustments thanks- thank thanks. RESULTS LATER TODAY or asap.
HOLY MOKEY- it works- I SHORTED THE WIRE FEED MOTOR WIRES TOGETHER-AFTER THE MOTOR POWER WAS TURNED OFF AND IT STOPPED THE MOTOR NICLEY_ SO THATS THE FIX- THANKS 100 TIMES OVER. YOU ARE AN ALL-STAR - THANKS GORAN-K THE most perfect answere.
There is probably a capacitor somewhere either between the trigger and the relay, or on the motor controller, where it is ‘smoothing’ pwm to a dc analogue signal.
If it is on the trigger, you might be able to use a resistor between power and ground to bleed it out faster. If it is in the speed controller, I would try shorting past it. I don’t think it is actually needed.
the cap might act as a flyback which if you spin the motor backwards, it will generate current back up the circuit. flyback stop that, but they are usually diodes. look to see if there is a diode before or after that. There should be as capacitors aren’t typically used for that purpose. But have and should have are two different things.
The other way and probably easier to do it, is get a normally closed relay (and it might be the same part number), and put it and a resistor between the two motor wires where you shorted it. You need some resistance so you aren’t shorting out the power supply directly, they burn up that way… You hook the same trigger wire to it, and it will latch open and when the other one closes and vice versa.
Kevin you are seeing the mass of the wire spool free wheel the the motor with inertia. The shorting of the motor is probably exactly what the orginal board did. You can definitely find a time delay relay that has the correct voltage and current requirements for your motor with the time scale you need. I would try looking in allied electronics for one. Simply put the time delay on shorting the motor after removing power and it will let you dial in a stop delay time. The time will probably need to be adjusted as the spool runs out as it will be based on inertia keeping the spool turning.
THANKS SEAN-O and DAN-A— for the extra info- I was looking for a timed relay- just not sure what to type in too get a timed NC relay or normally closed relay- I will try your type in names to find a timed NC relay this time see i can find one adjustable. I canceled my other order of a non adjustable one.THANKS,- I Was having wire burn back in my tip just before my original motor control circuit board stoped working.
ANY ideas on what time scale i would be looking for- i think its maybe less than a second- I seen one 24 dc volts adjustable to 0 too 15 second- though i think maybe need one in the ms range-- not sure what ms range might be.?THANKS.
I would try short past the cap on the speed controller first. You just need to solder a wire across the two pins.
You might be able to get a long enough delay by putting a cap in between the trigger signal and the relay, that may keep the relay energized for a second or two.
What is relay part number?
I got power going to the 24 dc volt transformer coming from the main power contactor- since it still engaged with the trigger on the mig gun- It was 220 v ac too transformer-The gas valve and the main contactor solinoid still works probbly off the circuit board. So i would not be sure ware i would try adding a cap or resistor in my circuit- ? The only power i could find that turned on and then off with the trigger switch- was off the main contactor- 220 v AC. so that’s ware i am at on wiring’ mostly half LOST.
OK if i find a timed relay normally closed-24 volt DC about 20 amps for extra suge capacity- my motor is 10 amps- you still think i need a set of resistors between the 2 shorting wires negitive and positive wires- i wounder what type or size resistors might be best try.
Actually I am just wondering, if the pwm control module capacitor is powering the motor for the extra 4 seconds, if you cut that say in half with a smaller capacitor (capacitance), that might actually cut the delay to 1-2 seconds without doing anything else.
I bought a motor speed controller on ebay and don’t want to mess with the caps because i have little experience in that area of knowlege- what about the adjustable relay and an adjustable resistor in between shorting wires- what kind of resistor would work and be adjustable with in the range? needed? THANKS
EVEN when i unplug the motor manually- the rollers keep spinning a few inches of wire. HEADING back to the shop for now,i only have very little bit left to weld before my wood truck is done so waisted wire not a problem for now. THANKS
which one? I will look at it, depending on which one it might be really easy.
I am not sure how to transfer amizon link to dow to show it-or how to transfer from ebay or amizon links to DOW–also i bought a NC-NO- relay to get the motor shorted when letting off the switch-that might be here this thursday from amizon prime fast shipping deal. though no time delay on it. And all i have is a note book labtop-no apps like cell phone would have.------https://www.amazon.com/dp/B00JEXJXAC?psc=1&ref=ppx_yo2ov_dt_b_product_details.Now i try too load power supply from bookmark saved page.Amazon.com next the relay to short the motor when power is off–https://www.amazon.com/gp/product/B07FCVM7LB/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1----this what i got so far too power the wire feed motor 10 amp 24 volt. the power supply only 10 amps- though motor probbly not pulling full 10 amps at slower wire feed speeds.?–LATER nap time past-too much coffee me had,