Hello,
I have just designed an SMPS for bench use at work and was thinking about Earthing the chassis. However, when i metered the mains socket outlets i found that Mains Earth and Mains Neutral are connected together.
Does anybody know if this is supposed to be so?
I thought that any current...
Hi,
The need is not generally for really high spec supplies like BobbyNewmark described one.
But in UK, a 0-30V, 2A power supply would cost something around $350.00 and hence its thought worthwhile to look into making them.
There is flexi-time and it'd be difficult to check everyone over...
Hi,
Actually some of the power requirements are more complicated than just 5 volts for micros. Sometimes its split supplies or 24V at 2Amps etc etc. In fact, the 24V supply that I used to use disappeared, and I now use a supply which was ripped out of a PC for that 24V. It's considered that...
Hi,
Unfortunately , we're not buying more as they keep going missing....not only that, but i think that once ive gotten the hang of it, i'll be able to make them very cheaply to any spec we would need. At the moment we have engineers going to the production dept begging production staff to make...
Hi, Thanks for replying....sorry my diagram is misleading concerning the position of the primary current sense resistor.....in the actual circuit it is between pins 13 & 14 as in the app note.
The transformer is RM14 ferrite core set ungapped,8000nH (AL) N67 (Epcos Manuf No. = B65887ER67)
-the...
Dear Engineers
Our bench power supplies having been going missing from work (people are allowed to “work from home”) and I have been asked to make some. I have tried out a SMPS power supply with TL497, but have encountered problems in my investigations….
(My scope is a cheap $200 (new) type...
Hi,
Thanks for your replies. The power supplies that i'm making are just for in-house use in my company -since the bought-in supplies that we have keep going missing.
It's not for an assignment, i graduated in 2002 (Bachelors, Electronics).
I've had too much difficulty getting a few pieces of...
Dear Engineers,
I have designed a Flyback SMPS and V(out) needs to be regulated to 5V. Feedback of output voltage needs to be isolated and so I proposed to use the LM3411-5 precision secondary regulator feeding into an opto-coupler (4N27) which links up with the comp pin on the controller IC...
Thankyou for your replies. I've certainly learned a lesson here. i think Mike Halloran was right with "Sometimes the test is not what you first think it is."
At the time, it was obvious that my work samples weren't going to a customer and i just assumed that they wanted to see me do my best...
Dear Engineers
Sorry that this is about soldering, it's just that i'm an electronic engineer inbetween jobs....today a recruitment agency kindly sent me for a soldering test at a local electronics company so that i could hopefully do some soldering work till the next electronics job comes...
Hello,
It is required to send digital data over two miles of cable which is underground in a remote area.
It has been suggested that the serial digital bit stream is converted to an FSK signal, then sent over the two miles.
1.2KHz is to represent the logic low
1.4KHz is to represent the logic...
Hi, Thanks for your replies. There is just a suggestion in the company that they may want to re-design. I dont want to make any rash suggestions as its not really been in my department but it would be interesting if it could be made more efficient/more reliable/quicker & easier to build and...
Dear Engineers,
I am interested in re-designing an existing SMPS to make it more efficient and hopefully simpler to produce.
The existing SMPS runs off a battery and converts 8-30V DC to 5.6V DC. It is a non-isolated buck converter. There is no controller IC. -The control circuitry is all...
Hi,
I am getting back into drive testing and am hoping to clear up a safety issue first, due to a previous accident...
Myself and a colleague were doing tests on electric drives. The drives had a three phase 415V (rms) input which was fed to a 6 pulse diode rectifier. This then produced the...
Thanks for replying. I have got it working in the lab with the 100 metre cable without the line drivers -but appreciate that in the "field" i could get noise problems -however, i doubt the source antenna will be a problem -as we only transmit a maximum of 10dBm, -also, since the dish antennas...
