Re: [Repeater-Builder] Re: Monitoring Positive Ground 48 to negative Ground 0-5
Does your digi have a serial port? Can you send and receive data in and out? Maybe this might work... http://www.linuxtoys.org/dvm/dvm.html or this... http://www.viddata.com/dvm_hardware.htm or this... http://www.rs232pro.com/rs232/rs232_dvm_kit.htm Mike WA6ILQ At 02:42 PM 01/30/10, you wrote: Yes, trying to monitor the local -48 Power system, and solar charging system with my APRS digi +12VDC that accepts 0-5VDC input. Chuck skipp025 wrote: Chuck Kimball mailto:n0...@...n0...@... wrote: Speaking of monitoring Anyone have an easy way of converting a Positive Ground 48 to 72 volt system to a Negative Ground 0-5V for monitoring? Do you want the voltage to vary with change in the 48 to 72 volt dc supply? s. Yahoo! Groups Links (Yahoo! ID required) mailto:repeater-builder-fullfeatu...@yahoogroups.comrepeater-builder-fullfeatu...@yahoogroups.com
Re: [Repeater-Builder] Re: Monitoring Positive Ground 48 to negative Ground 0-5
If you made a simple voltage divider that would give you around 12VDc from the 148VDC power plant you could use a circuit like this to watch the voltage change: http://dev.emcelettronica.com/howto-monitor-lead-acid-batteries-charge The LM3914 would give you high/low outputs at the LED lights to trigger an input? You'd have to do some experimenting. 73, Joe, K1ike skipp025 wrote: Chuck Kimball n0...@... wrote: Yes, trying to monitor the local -48 Power system, and solar charging system with my APRS digi +12VDC that accepts 0-5VDC input. Chuck The next part is how much resolution and accuracy do you want? There are a number of ways to fudge fixed step reporting but a truly isolated circuit with scaled voltage tracking is a more detailed animal. s. Yahoo! Groups Links
[Repeater-Builder] Re: Monitoring Positive Ground 48 to negative Ground 0-5
Chuck Kimball n0...@... wrote: Speaking of monitoring Anyone have an easy way of converting a Positive Ground 48 to 72 volt system to a Negative Ground 0-5V for monitoring? Do you want the voltage to vary with change in the 48 to 72 volt dc supply? s.
Re: [Repeater-Builder] Re: Monitoring Positive Ground 48 to negative Ground 0-5
Yes, trying to monitor the local -48 Power system, and solar charging system with my APRS digi +12VDC that accepts 0-5VDC input. Chuck skipp025 wrote: Chuck Kimball n0...@... wrote: Speaking of monitoring Anyone have an easy way of converting a Positive Ground 48 to 72 volt system to a Negative Ground 0-5V for monitoring? Do you want the voltage to vary with change in the 48 to 72 volt dc supply? s. Yahoo! Groups Links
Re: [Repeater-Builder] Re: Monitoring Positive Ground 48 to negative Ground 0-5
At 02:42 PM 1/30/2010, Chuck Kimball wrote: Yes, trying to monitor the local -48 Power system, and solar charging system with my APRS digi +12VDC that accepts 0-5VDC input. You need a DC-DC converter. This should help you get started http://www.maxim-ic.com/app-notes/index.mvp/id/2031 Ken -- President and CTO - Arcom Communications Makers of repeater controllers and accessories. http://www.arcomcontrollers.com/ Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp.net We don't just make 'em. We use 'em!
Re: [Repeater-Builder] Re: Monitoring Positive Ground 48 to negative Ground 0-5
Chuck Kimball wrote: Yes, trying to monitor the local -48 Power system, and solar charging system with my APRS digi +12VDC that accepts 0-5VDC input. Chuck Probably the simplest would be to use an opamp as a X 0.1 inverting amplifier: 10K --/\/\/\/\-- | | 100K| |\ | -48v ---/\/\/\/\-|-\ | | |-- to controller 0 to 5v input gnd--|+/ |/ The scale factor will be -10:1 on your controller (ie a reading of 4.4V would mean -44 volts at the battery). If there is any possibility of losing opamp power while connected to the -48 volts, you should also place a Schottky diode from the opamp -input to ground (cathode to opamp and anode to ground). Ed Yoho W6YJ
Re: [Repeater-Builder] Re: Monitoring Positive Ground 48 to negative Ground 0-5
How about a Optoisolator? Like a 4N25, I'd use a 47K resistor on the LED side and play with the resistor value on either side to get the readings right, but its what they do in switch mode supplies to make the DC side talk to the AC control circuits.
[Repeater-Builder] Re: Monitoring Positive Ground 48 to negative Ground 0-5
Chuck Kimball n0...@... wrote: Yes, trying to monitor the local -48 Power system, and solar charging system with my APRS digi +12VDC that accepts 0-5VDC input. Chuck The next part is how much resolution and accuracy do you want? There are a number of ways to fudge fixed step reporting but a truly isolated circuit with scaled voltage tracking is a more detailed animal. s.
