# External Power Suppy - Nikon Coolpix 5700

Discussion in 'Nikon' started by Donald Gray, Oct 22, 2003.

1. ### Donald GrayGuest

I am interested in making a regulated (stabalised) external power
supply for my 5700 which needs 8.4 volt input.

Can anyone help with a suitable circuit?

(Source Voltage probably 9 or 12v)

Tks
--
Donald Gray
Putting ODCOMBE on the Global Village Map!
www.odcombe.demon.co.uk
You do not have to email me, but if you wish to...
Thanks

Donald Gray, Oct 22, 2003

2. ### Donald GrayGuest

Does anyone know the voltage latitude and current needs of the 7500?

Thank you
--
Donald Gray
Putting ODCOMBE on the Global Village Map!
www.odcombe.demon.co.uk
You do not have to email me, but if you wish to...
Thanks

Donald Gray, Oct 22, 2003

3. ### Donald GrayGuest

Olin,
Thanks for the comments and the offer.

In reality, I was being very lazy and hoping someone had such an
instant circuit - hence my enquiry. I didn't want to re-invent the
wheel. (It is 10 years since I did any design work & homebrew!)

Last night, I decided to reinvent it and have designed a voltage
regulator - stabiliser based on the LM371 which has an Imax of1.5A

The output volts (Vout) is dependant on the ratio of two resistors, R1
& R2, being used to set up the reference voltage. The formula being:-

Vout=((R2/R1)+1)*1.25

So, for my needs (8.4v), R2=4k7 & R1=820R which gives 8.41v

Note: the source (input) voltage should be at least 2.5v higher than
the Output voltage. That suits a (nominal) 12v source

The cost of the stabaliser project is about 5 UKpounds, say 6-8 USD

If anyone is interested, I have done the calculations to give
stabiliser voltages from 1.9 volts to 27.2 volts utilising standard
(E24) series resistors, I will email a copy. It is in an Excel
spreadsheet format. (Don't forget to remove the safetypin from my

I am assembling the few components and once completed, I will write it
up and publish the info for anyone interested in having external
battery power.

Regards to all

[snip]--
73s OM
Donald G3YPL/exZL1AZC
Putting ODCOMBE on the Global Village Map!
www.odcombe.demon.co.uk
You do not have to email me, but if you wish to...