Ohhhh Yeaaaaaa!!!
With that much current it is not hard to do at all.
I just fused a couple feet of some 22ga. feeding an FET that blewout and shorted the other day!!!!
It happened so quick I had forgot there was a switch on the supply to turn it off by!!! He,he,he,he
It welded the wire solidly to the molex connector it was shoved into for the connection to the circuit!!
Fun, Fun, Fun !!!!!!
jer 🙂
With that much current it is not hard to do at all.
I just fused a couple feet of some 22ga. feeding an FET that blewout and shorted the other day!!!!
It happened so quick I had forgot there was a switch on the supply to turn it off by!!! He,he,he,he
It welded the wire solidly to the molex connector it was shoved into for the connection to the circuit!!
Fun, Fun, Fun !!!!!!
jer 🙂
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😀 lol...have you ever seen a TDA7293 explode? It's awesome, ran it on +-33vdc with a 4 ohm load and it just blew in my face after 20 seconds of playing bass music. 2 amp fuse never even popped.
No, but I had a FET hit me in the face once and a TO-92 shoot across the room before.
I have had electrolytics go off like M-80's as well.
Those 22ga. wires got cherry red and now they are bare 22ga. wire!!!
I wanted some high current and it blew the fuse the first time so I bypassed it (It is not advisable to do this in common practice).
I got high current the second time around!!!
The FET was a 216watt 170amp from T.I. and it handled the 15v side at 15amps just fine.
But it didn't fair well on the 32v side, my 20 amp meter overanged and blanked out so I have no idea what the peak current was.
http://www.ti.com/lit/ds/symlink/csd18532kcs.pdf
That is good to know about the TDA7293 as I just got a bunch of those to try out.
I'm planning on paralleling them anyhow for to handle the 1 to 2 ohm range of my ESL's.
jer 🙂
P.S. Please be careful when dealing with this kind of current things can and will get hot very quickly and is powerful enough to melt and weld metal!!!
Building a high current regulator that has an adjustable current limit is advisable!!!
I have had electrolytics go off like M-80's as well.
Those 22ga. wires got cherry red and now they are bare 22ga. wire!!!
I wanted some high current and it blew the fuse the first time so I bypassed it (It is not advisable to do this in common practice).
I got high current the second time around!!!
The FET was a 216watt 170amp from T.I. and it handled the 15v side at 15amps just fine.
But it didn't fair well on the 32v side, my 20 amp meter overanged and blanked out so I have no idea what the peak current was.
http://www.ti.com/lit/ds/symlink/csd18532kcs.pdf
That is good to know about the TDA7293 as I just got a bunch of those to try out.
I'm planning on paralleling them anyhow for to handle the 1 to 2 ohm range of my ESL's.
jer 🙂
P.S. Please be careful when dealing with this kind of current things can and will get hot very quickly and is powerful enough to melt and weld metal!!!
Building a high current regulator that has an adjustable current limit is advisable!!!
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A bit of info for you guys.
The thin wires on the secondary are often connected to the thick wires of the same colour.
You will notice that the primary has a large winding, plus a smaller additional winding.
During normal charge operation, a relay cuts out the smaller additional winding, forcing a slightly higher output voltage out of this thin wires, allowing the transformer to charge the batteries.
During a power outage, the batteries cycle the thick windings with 60/50hz and a relay cuts the smaller additional winding in, allowing the proper voltage to be generated with the "modified square wave" waveform.
Also, on some transformers, the smaller additional windings are switched in and out with relays to allow voltage regulation for the load.
They make good power supplies, but you wont get a decent voltage out of one without using one out of a dual battery UPS, and even then only about 15 volts per rail.
If you drive the transformer without the additional primaries connected, you will get a bit more of an output.
ALso if you have a lot of the same type of transformers, you can connect the outputs up in series to get more voltage.
The thin wires on the secondary are often connected to the thick wires of the same colour.
You will notice that the primary has a large winding, plus a smaller additional winding.
During normal charge operation, a relay cuts out the smaller additional winding, forcing a slightly higher output voltage out of this thin wires, allowing the transformer to charge the batteries.
During a power outage, the batteries cycle the thick windings with 60/50hz and a relay cuts the smaller additional winding in, allowing the proper voltage to be generated with the "modified square wave" waveform.
Also, on some transformers, the smaller additional windings are switched in and out with relays to allow voltage regulation for the load.
They make good power supplies, but you wont get a decent voltage out of one without using one out of a dual battery UPS, and even then only about 15 volts per rail.
If you drive the transformer without the additional primaries connected, you will get a bit more of an output.
ALso if you have a lot of the same type of transformers, you can connect the outputs up in series to get more voltage.
I like watching things that shouldn't glow like an LED...well glow like one...lol
Rainwulf, I figured out the wires on my ups trans but not till I took some of the paper off.
I hooked 120v to the thicker primary and it blew a 2, 4, and a 8 amp fuse... a 10 amp fuse held but i'm sure the thick primary didn't have enough turns and so I just stripped the whole thing and re-wired the primary...I'll use the old primary to re-wire a high voltage dual ac secondary.
I followed this video Build an electric transformer (DIY) - YouTube
Rainwulf, I figured out the wires on my ups trans but not till I took some of the paper off.
I hooked 120v to the thicker primary and it blew a 2, 4, and a 8 amp fuse... a 10 amp fuse held but i'm sure the thick primary didn't have enough turns and so I just stripped the whole thing and re-wired the primary...I'll use the old primary to re-wire a high voltage dual ac secondary.
I followed this video Build an electric transformer (DIY) - YouTube
"If you drive the transformer without the additional primaries connected, you will get a bit more of an output."
Mine have a red wire that doesn't seem to connect to anything, I planned to cut that off if I use them.
Mine have a red wire that doesn't seem to connect to anything, I planned to cut that off if I use them.
That may have been connected to an inter turn copper shield, or a temperature sensor/fuse.
Most of the cheap powerware 3xxx series inverters i pull apart have a few useful parts, the most useful being the 12 volt coil relays, the various power mosfets and the 3 pin regs on board. Plus a few nice X2 caps as well.
You have to be careful though as some of those relays have led a hard life switching 240 on and off out of switch mode PSU's.
The transformers i get usually have a centre split secondary, with a massively thick red wire that goes directly to the battery positive, and then a white and black wire that go to each side of the half wave chopper, that gets alternately earthed via some high current mosfets to create a transformer half wave chopper.
There is also a thin white and black and red wire that hooks up to the same windings, but go to a little LM317T regulator module to charge the lead acid gel cells through a half wave rectifier using fast diodes. This also has the added side effect of acting as catch diodes for any inductive kick back. Everything in these cheap little units is designed to have multiple uses to save money and components.
The primary side has 3 wires, between 2 is the bulk of the ac side, with the third wire switching in/out what i measured to be around 5 percent of the main primary winding turns.(massive guess work, will need to be tested properly, i just used a ohm meter)
The reason for the AC side switch is that a "ac modified" output actually has to have a fairly high RMS voltage to be equivalent to a sine wave output, but when operating in reverse, the output voltage isnt high enough to satisfactory charge the gel cells.
Another use of two matching UPS transformers is hooking them up back to back, (secondary to secondary) and making a really good isolation transformer.
They are also useful for bucking/boosting transformers as well, and they have a 135 degree C temperature rating too. They are hardy little bastards.
Some other UPSs just have a single 7-8 volt secondary and are driven in full wave chopper, but they are often a bit more expensive due to the requirement for twice as many chopper transistors. They save in copper though.
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