I'm not referring to a snubber circuit. My problem is that the relay I use (and I can not change it)needs minimum 12V and 100mA on its contacts to work properly. It is a Schrack (Tyco Electronics) RT31L12. I use the change over contact to know if the relay is ON or OFF. OK now back to my...
Hello, I've heard that a capacitor placed parallel on the contacts of a two poles relay help them to stay clean. My question is what should be the value of such capacitor? The maximum voltage is 253Vac, so the capacitor should be a X1 type (because there is no fuse to protect the system).
Thanks...
Hello, I want to use a FET as current source by using its symetrical characteristics; but the problem is that the voltage can variate from 24Vac to 253Vac. I need about 1mA.
All any other suggestions are welcome of course, but nothing with a serial capacitor or resistor divider. Thanks a lot...
Hello,
There is a Harris HV-2405E. Input: 15Vrms - 275Vrms, Dual output voltages available, Ouput Current up to 50mA Output Voltage 5V to 24V.
There is also a Supertex SR036 and SR037 but Vout is only 3.3V and 5.0V
You can always put a 1:1 transformator if you need a isolation.
I hope this will...
buzzp, The schematic is very simple: Foom the positive point of the power supply dedicated to the relay(s) go directly to the coil of the relay the other side of the relay coil is connected to the collector of a transistor (BC547 e.g.) the emitter of the transistor is connected to the ground...
MIssunderstanding again! What I wanted to say is that you don't have to hesitate to ask me things. I give my e-mail because it is more easier to send files than to write a long explanation. I'm really soory if I hurt someone ; it was and is nver my goal.
Hello! I've made a lot of tests! You know already the context... The schematic is the following (where can I ask if it is possible to put a schematic or ask to devlop something that make it possible?) The power supply (+) line go to one point of the relay coil, the other side of the relay coil...
Hello everybody! Thanks a lot for the star I receive!
I've tried another solution but have to test it deeper before; just to be sure...
Using PWM can spare a lot of energy. A relay may so be driven at a frequency which may not be under the 100Hz. I made a try at 10KHz with a duty cycle of 50/50...
have a look at http://www.piclist.com/techref/io/relays.htm
and but there is a fault in the schematic (the cap near the relay must be take off and there must be a free wheel diode on the relay coil also the diode near the undesirable cap must be also be taling off)and the left side of the...
I have to re-use existing used relays. I'm not sure that PWM will help to reduce the consumption. I've read that the hold current must be at all times above the minimum holding current.So, each time it would be under that value the MAX peak should be higher. This means that I win nothing. The...
I never guess that it would be so difficult to make me comprehensible! I thought that what I was writing was clear. My first question was, in fact, a schematic which let me drive a relay (whatever which one) with the half of the voltage it need. I didn't give more infos because I thought it was...
I'm sorry guys but I'm still looking for a schematic which let me drive a 24Vdc relay with only 12Vdc.
OK! By writing this I just understand my error! I'm really sorry for this ! Because englsh is not my mother language I was focusing on what I was writing in place of the data I have to give...
Yes, indeed you're right.But the 12Vdc relay has a max voltage of 30.6Vdc while the 24Vdc has a max voltage of 61.2Vdc. Because the voltage I receive is 30Vdc +5% -30% I prefered to choose the 24Vdc one. 30Vdc minus 30% is 21Vdc and that's also above the 12Vdc nominal of the 12Vdc relay, but...
All right. I will try to answer all at one time.
That's true and I have calculate the capacitor value (220uF). In fact a relay has to be driven with current, the voltage is not so important. So, after be pulled-in the relay consumption will be 5.85mA for a 24Vdc and...11.69mA for a 12Vdc! My...
