Seeking info on Power Conversions "Slimline" inverter

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- who where
  
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posted
12 years ago

Tue, Sep 27, 2011 12:47 PM

I have a sine-wave inverter manufactured by Power Conversions P/L in Victoria. It is the "Slimline" series, 500 Watt. According to the current operators of PC, this was made by the previous management something like 15 years ago and they have no info on it.

On the rear panel is a 5-pin DIN socket, which apparently is for I/O functions - remote on/off has been suggested. (One interesting characteristic of this inverter is that if the DC input CB is opened and reclosed, the main [output] on/off switch has to be cycled to get the inverter to restart.) I have traced the DIN connector circuitry and it drives a pair of 4N35 optos.

Unfortunately exciting these optos doesn't cause any change in the device - if on it stays on, if off it stays off. If the "remote" function were to over-ride this it would make some sense.

I am hoping that someone out there has info or history on these and can shed some light.

- P
- Phil Allison
  
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posted
12 years ago

Tue, Sep 27, 2011 2:13 PM

"who where"

** You sure that pins 1 and 2 go to the DIN socket?

Remote status would be useful, ie battery voltage OK and operating or not.

... Phil

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- kreed
  
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posted
12 years ago

Tue, Sep 27, 2011 3:19 PM

It is very possible that it is some kind of serial data connection (probably RS-232) or similar. I have seen stuff like this in UPS supplies used with PC's. If there is a micro in there such as a PIC or AVR then this is very likely. Apart from turning the unit on and off, it likely provides data as to the battery voltage (how much charge it has left), the load current, operating temperature of the unit, fault reports and so on. It may also be possible to change these settings and activate/deactivate these and other options via a PC with the appropriate software. It is also possible that it connects to a custom remote control that is only available from the manufacturer, but a PC based setup is very likely these days.

If it is an RS232 or similar - then the optos are there simply to isolate the PC (serial port) from the electronics in the inverter, to protect the PC from high voltages that could occur on the RS232 lines in the inverter if it catastrophically failed, and also to prevent ground loops. There is typically one opto used for data in and one for data out in these designs.

Often this method is also used in ones with USB, except that it will connect to a USB/Serial IC and power for this isolated side of the circuit will come from the host PC via USB connector,

In this case, activating the optos as you described by just connecting them to a DC supply via a suitable resistor would do nothing. They would need a data stream of some kind and what rate, what format and what actual data to send is anyone's guess, and probably only can be discovered by a massive amount of trial and error.