7.26Volts output

Hello,
I am new to electronics and I have a project to interface an active
electrode that need a clean 7.26V (+- 0.02V) supply voltage. I would
like to use a 9V battery. The active electrode comsumes 0.7mA. Can I
simply use a series of resistors or do I need a voltage regulator or a
converter?

Thanks

Daniel Jeffrey

 

[martin griffith]

On 11 Feb 2005 10:40:50 -0800, in sci.electronics.design
danielj@hralloy.com wrote:

Hello,
I am new to electronics and I have a project to interface an active
electrode that need a clean 7.26V (+- 0.02V) supply voltage. I would
like to use a 9V battery. The active electrode comsumes 0.7mA. Can I
simply use a series of resistors or do I need a voltage regulator or a
converter?

Thanks

Daniel Jeffrey
9V is a "nominal" voltage, if it is a rechargeable battery it could be

as low as 8.4V.
have a look at
http://focus.ti.com/lit/ds/symlink/tl431a.pdf
this is a shunt regulator, which might suit you. Note that it needs a
minimum load, so you would have to put another resistor in paralle
with your electrode, to keep the total current above 1mA. Basic Ohms
law.
You could also look at low dropout regulators (LDO's) from say Ti.com
or national.com


martin


"Facts are stupid things.." -- Reagan, '88

 

[qrk]

danielj@hralloy.com wrote:

Hello,
I am new to electronics and I have a project to interface an active
electrode that need a clean 7.26V (+- 0.02V) supply voltage. I would
like to use a 9V battery. The active electrode comsumes 0.7mA. Can I
simply use a series of resistors or do I need a voltage regulator or
a
converter?

Thanks

Daniel Jeffrey

You could use a precision reference and an op-amp to scale the output
voltage. Your current requirement is well within the output current
capabilities of an op-amp.

There are numerous adjustable low-dropout voltage regulators which
would do the job.

Mark