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    DC Servo power supply help.

    Thank you for your helpful replies, I have ordered my parts to build up this power supply, hopefully it will work fine.
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    DC Servo power supply help.

    Thanks for the advice! So I've been looking a bit more into building this power supply, I can get a reasonably priced 54v 700w toroidal transformer, which will give me around 76.3v once rectified.... What sort of smoothing capacitance should I be looking for? I found a spreadsheet that works out...
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    DC Servo power supply help.

    Hello, I need to design a power supply for a machine that the control system has died on. The machine is quite old (1989 era...). There are 2 brushed DC servo's that drive 2 axes, these are both 65v, 4.5A, 200w each. I'm replacing the old servo cards and power supply so that I can drive them...
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    measuring 3 phase circuits correctly

    Thanks for the replies! The system is definitely a 3phase + neutral + earth. The servo drives are mains voltage drives and use 1 phase + neutral in the range of 220 - 240VAC. With no load I measured around 246V from each phase to neutral, once the drives were enabled the voltages I was able to...
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    measuring 3 phase circuits correctly

    Hello, I've just bought a new piece of machinery for my workshop and wired it into my 3 phase power, the same way as I always do. The machine powered up and worked fine until I noticed a fault showing up on 1 of the motor drives. When reading through the fault codes is states over voltage on...
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    Power supply help

    Thank again for the information, you have been most helpful and I really appreciate your assistance and guidance. I will order up some components and get this thing going :) Will try and post my findings as it might help others with similar projects. Thanks, Adam.
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    Power supply help

    Did you have a chance to look over the data sheet Steve? Thanks, Adam
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    Power supply help

    Hi STeve, I'm sure I replied to this yesterday, but for whatever reason it mustn't have posted... Here is the link to the resistor I was looking at getting, the 1K 25w for the bleed resistor is from the same range: http://uk.rs-online.com/web/p/products/1074197/ I've found out my timer relay...
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    Power supply help

    Thanks ever so much for this info Steve, its most helpful ;) I've put together a circuit diagram of the rough layout, just to see if I've got the right idea: Hopefully I'm not far off... I was thinking maybe of attaching a 10A thermostat to the soft start resistor, so in case the relay...
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    Power supply help

    This seems a sensible idea, they are pretty cheap I think anyway. If this this would be safer, then I'd be tempted to go with that. So I'd need something like a 12A 240V rated relay then? Also, would the resistor be the same value if placed on the 100V side? How do I calculate the realistic...
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    Power supply help

    Thats ok, I was just worried that I'd missed something. If I were to base the power supply on 11A, would my rectifier still be ok? Or should i up rate It? I like the idea of this :) what rating resistor can I use? I read a bit of a paper that suggested 50w 500R, but I have no idea... I could...
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    Power supply help

    Thanks for your reply Steve! I'm a bit confused with the values you calculated though? The manufacturer of the drive recommends *2000uF* per motor amp: 2000 x 7 uF = 14,000uF, so that would equate to 2 of my *7400uF* caps. Should I be aiming to design the power supply to cope with the power...
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    Power supply help

    Hello, I'm looking for some assistance in building a linear power supply for a machine that uses DC servo's. I am replacing some old drives so I can make use of the machine in a different way. The manufacturer of the new servo drives recommends that for every motor amp, 2000uf in...
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    Power supply help

    Hi Oliver, Thats a good point you raise, I have to check tomorrow, I can't remember in the primary and secondary taps without having another look. ;) Thanks, Adam.
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    Power supply help

    Hi Guys, I wonder if anyone might be able to lend a hand with helping me design a power supply for a CNC machine I'm retrofitting? Here's what I know: I have 3 x 140v DC servo motors each with a stall current of 35A, continuous approx. 6A. I have 2 x (1 more on order) DC servo drives...
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    Soldering Help

    Thanks for the reply Steve! I think i will definitely go with the method you recommended. De-soldering is something I've had fairly little experience at. Just another quick question, what wattage iron would you recommend? Unfortunately I've not got the benefit of a temperature controlled unit...
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    Soldering Help

    Hello, I'm looking for a little advice in repairing a PCI card for a PC. The card in question is an industrial data acquisition card with 64 isolated digital outputs. Unfortunately due to my own fault i think i have blown one of the darlington transistor arrays as i was only using 1 output at...
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