Voltage loss

Status
Not open for further replies.
I

ibwev

Member
When I power the attached circuit, the sensor reduces the voltage to the contactor to 7.5 volts. This is not enough voltage to operate the contactor. I could not find a datasheet on the sensor to know if I could safely increase the input voltage. What is the best solution to get another 4.5 volts to the contactor? (Maybe connect the sensor to a transistor to power the contactor?)
 

Attachments

  • circuit.png
    12.7 KB · Views: 152
What kind of sensor is it?

A transistor might be one option, but I'd suggest that you might be able to get a different relay - one with a lower switching current perhaps.
 
I see a transformer with what I assume to be a single 120 VAC primary and I see two secondaries in series and labeled 12 VDC? I do not see any rectification where we get from the secondary AC to DC? As drawn the circuit won't work. As drawn I see AC going to whatever that sensor is. You will need to provide more information about the circuit.

Ron
 
Ron,
what you're seeing as the second secondary is actually the contactor he is talking about. The transformer is a 220 to 12VAC.

Need sensor part number.
 
Mike odom said:
Ron,
what you're seeing as the second secondary is actually the contactor he is talking about. The transformer is a 220 to 12VAC.

Need sensor part number.
Click to expand...

Thank you. The circuit as drawn made no sense to me. ? I still don't get the DC part? Where would DC come from?

Ron
 
Mike odom said:
who said anything about DC (except you, of course)???
Click to expand...

Mike, I see VDC plastered on the drawing at least twice. So we have no clue if the contactor coil is 12 VDC or 12 VAC? We also have no clue what the sensor that is in series with the contactor coil is? We also have no clue what the contactor coil rated current should be? Anyway, besides me I would have to say the original poster said something about DC when it was plastered in the drawing.



Ron
 
You cannot have 12VDC coming out of the transformer, it's AC. What sort of sensor is it? If it's a simple switch that closes then you are connecting AC across your contactor/relay coil. Is the contactor/relay coil rated for AC or DC. What voltage?
 
Status
Not open for further replies.

Similar threads

S
  • Question
Linear voltage regulator?
Replies
8
Views
2K
Papabravo
V
  • Question
High voltage detection counter
Replies
16
Views
3K
vortex0606
V
Positive / Negative voltage circuit problem
2
Replies
20
Views
4K
ZipZapOuch
  • Question
Continuous, very small reverse voltage on electrolytic capacitor
Replies
7
Views
2K
Tony Stewart
F
  • Question
A Lossless snubber for pushpull SMPS?
Replies
2
Views
1K
Flyback
F
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…