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...
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...
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...
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...
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...
Hi,
We need a simple communication system for our outdoor antenna pattern testing range. The sender and receiver are separated by some 90 metres (Antenna frequencies are 1GHz upwards.). The receiver is up a 20 metre tower.
Please see rough diagram…....
It has been decided to send bytes on...
Hi,
I wondered if readers could offer any validation for this CMOS Switch Mixer for an AM receiver that i just designed? I have built the receiver and now seeking the 455KHZ IF filter. However, i am having second thoughts about my mixer and wondered if suggestions for improvement or opinions...
Hello
I have just designed and built the following simple AM superhet receiver.
and
It is just to receive the station on AM 1026KHz. The Mixer is a switching mixer and literally just switches the signal on/off at 216KHz using a 7555 timer and CMOS 4066 analog switches which are switched via...
Dear Engineers,
I have recently been testing some inductor values at work by switching 5V across the inductor in series with a known resistor and noting the rate of voltage rise across the resistor with a scope on "trigger and hold" mode.
-Anyway, while doing this i noticed an interesting...
