+/- 9 volts for Ophir Head

Hi Jem

Highly recommend the DC-DC route, makes it so much simpler

Here's my version of power meter
Attachment 33794

I'm using a 3watt +-15Volt unit though, I needed to use a slightly larger DC-DC converter as I'm running the display of the +15V side

For the battery aspect it has a 2500ma Lipo cell connected to a Sparksfun LiPo Charger/Booster http://www.sparkfun.com/products/11231 that handles the recharging of the LiPo cell from either a micro USB or an optional 5V supply and also steps up the LiPo voltage from 3.7V to 5V, it also include a low voltage drop out so you can't damage the battery. Makes it simple;)

It can also be powered from the USB port so if you do happen to flatten the battery you can still use it while it's recharging

I'm just looking for a nice case to fit everything into and then I'll make a PCB with it all mounted on to finish this off

Cheers
Troy

Hi jem
Yes i wiil be at lem
Tell ya what if you like what i am using
I will let you have. It at cost and build another
If you want ;)

Quote:

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Originally Posted by Jem

Looks good. Will the Ophir head take 12 volts though?

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hey jem, sorry i wasn't thorough enough
this little pcb uses a pair of ICs called 7812 and 7912 to regulate the voltage and yield +/- 12v.
if you swap these with a pair of 7809 and 7909 you are good to go (and the parts are cheap and readily available)


but badger's proposal looks more tempting, i have to admit that :)

Quote:

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Originally Posted by Jem

Looks good. Will the Ophir head take 12 volts though?

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Jem Don't believe I ever gave you the spec sheet download. It's attached.

Attachment 33799

Al.

Thanks Al, Thanks Chris, in fact thanks everyone :D

Let me have a think on this...

Maybe some inspiration:
http://www.krom-hout.nl/img/ophir_small.jpg

Download link for design files
NOTE: Drill file has a little error, the 2 holes for bolting it to the head should be M4

Looks good, but waaaay beyond my capabilities i'm afraid.

hey troy
is that a panel pilot you are using for the display ??
if it is i thought the resolution was only to two points ?? ie 1.58v you have three ? or did you set it to display three and not use all of them ?
i looked at using one but wanted to be able to display somthing like 1.599w .did you find a way around the two digit problem or did they do an upgrade
to something ?
thanks

Quote:

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Originally Posted by loopee

Hi Jem

Highly recommend the DC-DC route, makes it so much simpler

Here's my version of power meter
Attachment 33794

I'm using a 3watt +-15Volt unit though, I needed to use a slightly larger DC-DC converter as I'm running the display of the +15V side

For the battery aspect it has a 2500ma Lipo cell connected to a Sparksfun LiPo Charger/Booster http://www.sparkfun.com/products/11231 that handles the recharging of the LiPo cell from either a micro USB or an optional 5V supply and also steps up the LiPo voltage from 3.7V to 5V, it also include a low voltage drop out so you can't damage the battery. Makes it simple;)

It can also be powered from the USB port so if you do happen to flatten the battery you can still use it while it's recharging

I'm just looking for a nice case to fit everything into and then I'll make a PCB with it all mounted on to finish this off

Cheers
Troy

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Hey Badger

It certainly is a panelpilot display

The documentation is sparse on that and I discovered it purely by trying, but if you set the scaling that 9.99 = 9.999 you still get the 4 digits working properly

Attachment 34005

Possibly this is due to an upgrade as I am running the latest version

Cheers
Troy

Hi It would be quite easy to just place a couple of linear regulators in series with the +/-12V output of a mains powered smpsu.