At 01:06 PM 01/14/08, you wrote: >Hi All, I have a CSI-32 tone panel that will work at 120 volts ac or 12 >volts dc. We in the UK only have 240 volts ac and having had a look at >my very blurry electrnic copy of the service manual it looks like the >primary needs to have connections 2 and 3 joined together for 240v >operation. >Can anyone with a better copy of the cctt confirm this please? > > Thanks in advance........Cheers Dave G7UZN London
The only schematic I have access to is at <http://www.repeater-builder.com/other-mfrs/csi-32.pdf>, and in looking at it you are correct. The transformer has two primaries which when in parallel are for 120v, and in series for 240v. Note that the USA mains distribution system is based on 3-phase power, and the "240" in some situations is closer to 208v, and the transformer may have been built for 110 / 208-220 vs 120v / 240v . If you have a concern, and have access to a variable output transformer, sometimes called an autotransformer (a major brand here in the colonies is "Variac") you could do a quick test: Leave the primaries in parallel, and set the auto-transformer for 120v and measure the secondary AC voltage. Then change the jumpers to series, and set it for 208, and measure again, then ramp it up to 240 and see what the voltage is. If the 240 value is the same as the 120 value, then it's not liable to burn up on you. CSI has been out of business for years, you may have a problem getting a replacement. Dave, if the transformer in the CSI gets hot on 240v you could get something like this: <http://www.allelectronics.com/cgi-bin/item/PS-12150/480/12V_1.5A_SWITCHING_POWER_SUPPLY_.html>. Just cut the plug off and put a local plug on. Note that the input is 100-240vAC. I've got several 12v devices around the house that are running on some of the above 12vDC 1.5a switching wall warts. Mike WA6ILQ
