Induction brass annealer redux
- Thread starter Gina1
- Start date
Why does your ammeter turn off then? If the 48V PSU shuts down the 12V PSU should still be working and the ammeter lit.
Again it looks like your PSU is shutting down rather than limiting. See here under "protection":
You can test the PSU separately by using a simply high power resistor. (Just the Meanwell with
nothing else in the equation except the PSU and the resistor.)
With the PSU set at 48V (untrimmed) the above resistor will pull 6A from the PSU. The resistor will get hot very quickly (you're asking it to dissipate 288W versus its rated 200W) but it should be ok for long enough to determine if the PSU is poked.
Again it looks like your PSU is shutting down rather than limiting. See here under "protection":
You can test the PSU separately by using a simply high power resistor. (Just the Meanwell with
nothing else in the equation except the PSU and the resistor.)
Amazon.com: Dpofirs 200W 8Ohm 8R Aluminum Case Wirewound Resistor, High Power Chassis Mounted Resistor, Industrial Eletrical Equipment Supplies : Industrial & Scientific
Amazon.com: Dpofirs 200W 8Ohm 8R Aluminum Case Wirewound Resistor, High Power Chassis Mounted Resistor, Industrial Eletrical Equipment Supplies : Industrial & Scientific
www.amazon.com
With the PSU set at 48V (untrimmed) the above resistor will pull 6A from the PSU. The resistor will get hot very quickly (you're asking it to dissipate 288W versus its rated 200W) but it should be ok for long enough to determine if the PSU is poked.
I have the distinct feeling this is the completely wrong ammeter....
Well it will only go into shutdown in an over voltage condition or over temperature condition or it's broken. You can read the voltage with a simple voltmeter across the output terminals and drop a case in the coil to see what happens. If it stays within voltage and it's cool then I'd say there's a fault with the PSU.
I just checked, no, the voltage goes up 2 volts right when I close the contactor then it quickly drops to the original setting.
With no case in the coil, voltage set to 44, I get 7.2 amps. With a case in the coil, voltage the same, I get 9.4 amps. With a case in the coil the amperage will slowly rise however the power supply trips after being at 9.5 amps for a few seconds.
My volt/ammeter is different than the one in the original parts list, that one wasn't available. Mine doesn't use a separate 12 volt power supply.
Last edited:
I'm not familiar with the power supply you are using. However there generally are two modes of overcurrent protection. In one case the power supply just shuts off and supplies no voltage or current. The other case is it limits the current to a safe value dropping the voltage all the way till zero in order for that to happen.
Sounds like what's happening is when you put a case in the coil the current exceeds what the power supply thinks it's safe and shuts down. So your power supplies is acting like the first case protection mode.
Sounds like what's happening is when you put a case in the coil the current exceeds what the power supply thinks it's safe and shuts down. So your power supplies is acting like the first case protection mode.
I agree. I wrote Jameco Electronics about the issue, I hope they’ll exchange it. I’m hoping for shorter run times and some of that glow so many people are able to achieve.
I provided a link to the spec sheet for the supply including its protection mechanisms. You tested the voltage condition and I very much doubt there's a temperature fault. So it's clearly not behaving correctly. Hopefully Jameco will exchange it.
Yes but note in your image
V+ comes from the PSU driving the load (the annealer). Just make sure the volt/ammeter can handle a 48V supply. (In all other respects it is wired as other meters of this type. The return from the load is passed across the shunt. The ammeter measures the voltage drop across the shunt (thin wires shunt to com and Ain) and from that deduces the current given the resistance of the shunt is known.) V+ still needs to come from somewhere. The diagram on the right has it coming from the load PSU. The boxes on the left - which aren't checked - reference either an 8-18V V+ range or a 3.5-30V V+ range. Note also the message "please use isolated power to supply the meter". I don't think this is the source of your PSU issue but check the ammeter specs to ensure it can handle 48V as it's power source V+ (quite separately it may measure a wider range than its applicable supply range).
Yes but note in your image
V+ comes from the PSU driving the load (the annealer). Just make sure the volt/ammeter can handle a 48V supply. (In all other respects it is wired as other meters of this type. The return from the load is passed across the shunt. The ammeter measures the voltage drop across the shunt (thin wires shunt to com and Ain) and from that deduces the current given the resistance of the shunt is known.) V+ still needs to come from somewhere. The diagram on the right has it coming from the load PSU. The boxes on the left - which aren't checked - reference either an 8-18V V+ range or a 3.5-30V V+ range. Note also the message "please use isolated power to supply the meter". I don't think this is the source of your PSU issue but check the ammeter specs to ensure it can handle 48V as it's power source V+ (quite separately it may measure a wider range than its applicable supply range).
If the power supply can go to 7.2 amps there is no reason not go to full load. It's something wrong in the ZVS, coil, case.
What is the material, caliber of the case?
Check for partial "short" in the coil.
Check the polarity to ZVS. Use both ZVSs that you have.
Check the Power Supply with some load - use a bunch of 100 watts bulbs (it's cheaper)
Exclude the amp meter
The PSU is going into shutdown protection way before it hits current limiting. It's meant to current limit - and not shut down - at 125% of its rated power. He doesn't get anywhere near close to this. It is only meant to shut down (which it is doing) in a voltage overload or over temperature condition. He's tested for the former. I doubt the latter exists.
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.