intercom power supply

[wyatt20019]

we have some portacom units but no power supply, would a clear com power supply work? like this one

NEW CLEAR COM PK-5 INTERCOM POWER SUPPLY - eBay (item 150285258622 end time Aug-26-08 15:07:52 PDT)

[cutlunch]

They would probably work together. Someone will be a long soon who will know more.

The Clearcom puts out 24V as opposed to the Portacom units which use 22V.

2 Volts shouldn't matter in this case.

But you need to get hold of a manual for both the portacom and clearcom units to make sure they apply power on the same XLR pins. They should do but you need to check first.

[waynehoskins]

I thought CC was 28 or 30 volts.

In any event, it's likely to work. Most all of the production intercom systems out there use a 28-32 volt dc power supply on pin 2 with respect to pin 1.

I also made my own from spare parts for free.

[SHARYNF]

Clear com is 30 volts DC typically at 2 amps for the larger powersupplies (usually this spec if for 50 beltpacks or 15 stations)

Sharyn

[wyatt20019]

i dug through some old power adapters and found these.

adapter 1: input:100-120V, output: 24V----0.75

adapter 2: input: 120-127 69hz, 350mA, output: 30v---500mA (AC power adapter) http://cgi.ebay.com/AC-DC-POWER-SUPP...3286.m20.l1116

would one of these work?

[waynehoskins]

Old wall warts are pretty dirty .. but I have managed to power a CC-compatible pack directly from a 12-volt wall wart before (or even a nine-volt battery). Since CC PL has a dry audio bus, it's less critical how clean the supply is than on an RTS system.

Those power adapters, are those AC or DC outputs? It would be rather a simple matter to cobble together a filter capacitor bank and a regulator circuit to clean those up. The 317 takes about 3 volts off the top, so if that's DC I'd take the 30 volt supply because there's more to cut off. If AC, I'd take the 24 volt supply since that'll make about 32 volts DC, which will clean up nicely, and be able to supply more current.

If I had the choice, though, I'd get a good beefy iron transformer. The one I used came free with the chassis! (my schematic and photos at crossroadsofarlington.org/wayne/rts-psu )

[wyatt20019]

the 30V one is DC. not sure about the other one.

[wyatt20019]

so how do i set this up? can i just solder the hot wire to pin 2 of an XLR head? or do i have to have the capacitor thingy?

[waynehoskins]

Originally Posted by wyatt20019

so how do i set this up? can i just solder the hot wire to pin 2 of an XLR head? or do i have to have the capacitor thingy?

Hot, no. That goes to the transformer primary along with neutral.

No matter what kind of supply you use, you'll end up needing beefy filter capacitors: if a homebrew supply, to filter ripple; if a wall-wart or cheap supply, because they don't have much filtering if any inside there. I used a pair of 2000-mike electrolytics to provide 4000 mikes , and that should be pretty fair. That's just a plain linear supply: transformer, diode bridge, capacitor, and that's usually pretty good; but I threw the 317 on the end to clean it up even more.

[wyatt20019]

so what do i need on top of this? http://cgi.ebay.com/AC-DC-POWER-SUPP...3286.m20.l1116 and how do i do it?