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NormComtois
Oct 21, 2009, 02:19 PM
Hi!

First time "asker"!

I have recently built a device for medical use, so electrical safety for the patient is of upmost importance.

I currently use a medical grade switching Power Supply +/- 15VDC (IPD, model SRP-25-2005). An AC inlet, IEC 320, brings Line and Neutral power to a medical grade illuminated DPST (Multicomp, model MC3811-091), which in turn is connected to the power supply. Hope this makes sense!

I would like to modify my current setup:

1) Make the neutral continuous to the power supply without interruptions. It is currently connected to one pole of the rocker switch
2) Use the +15VDC of the power supply to activate the light in the switch once it is "On"

My question to you all:

1) How can I do this?
2) Do I have the right equipment (switch, power supply... )

A simple diagram would be greatly appreciated!

Thanks!

Norm

Stratmando
Oct 21, 2009, 03:34 PM
Computers switch the neutral as well, I would have the neutrals tied together(not through switch)You don't want to use the Power switch, you will need to tie the new LED into the 15 Volts out. Dropping resistor will be needed.
If you use an LED, I will supply the formula for the size resistor.

KISS
Oct 21, 2009, 03:49 PM
The datasheet is here: http://datasheet.octopart.com/MC3811-091-02-Multicomp-datasheet-537372.pdf

But it's unclear.

There probably should be some markings for line and load. If line is 240 V and connected to the LINE terminals, then the switch should illuminate when on. One might assume that it will work on 240 VAC as well.

The LOAD terminals are not required to be connected.

Your power supply is of a universal design, so I'm unsure what the line voltage markets are.

I would suggest you contact Multicomp after verifying that the power cord is connected to the line terminals.

Post any terminal designations from the bottom or side of the switch.

KISS
Oct 21, 2009, 04:46 PM
Take a look at this datasheet:

http://www.rjselectronics.com/pdf/pad_PRS.pdf

Note that you have to specify a lamp voltage because they are wired with a line and a load side.

The RA9 has two small terminals for an LED, but is only SPST.
The LED is usually current driven with about 15-20 mA. Thus to illuminate it, you would chose R near a standard value and select it to be less than or equal to R = 15/20 mA. A 1K resistor would give 15 mA.

For R = 15/20 mA would yield a 750 ohm resistor is a standard value and could be used. Then the power disipation must be checked P = I^2*R = 0.02^2*750 = 0.3 W

So, a 750 ohm 0.5 W resistor would work. LED's are polarity sensitive. Usually you would put the resistor in the positive side of the power supply.

Stratmando
Oct 21, 2009, 05:57 PM
You say you want an indicator on the output, How ever when Main Power is on, isn't Low Voltage present at the same time.
An easy solution is a Bulb Across the Low Voltage output.
For High Voltage, Check out the lumminated Appliance Rocker switch here, check out 4th from the bottom of the page:
Rocker Switches (http://www.wiringproducts.com/contents/en-us/d88.html)
Edit, just looked at kisses, rockers, The're fine.

KISS
Oct 21, 2009, 06:09 PM
But he wants medical approval. Not sure if the rockers I referenced have that.