Is there any standard simple ckt which will convert Arduino output (1 to 5VDC) to 4 to 20mA 24VDC loop power?

[MMS79]

Hi,

i have used the below mentioned circuit to convert Aruduino output 1 to 5 VDC in to 24VDC 4 to 20mA.

and provided as a input to I to P converter (which in turns opens control valve).

The drawback of circuit is it drops voltage at 2VDC i.e. 8mA current up to 17VDC. due to which control valve doesnt open up.

at 3VDC i.e. 12mA it works fine.

please provide simple solution.

Regards

MMS79

[PaulG.]

I use a pwm output, boost it with a ULN2003 to 24V with a 1K 1/2W pullup resistor and drive a PWM input 0-20mA out signal conditioner. HE-X series from Omega. These devices were built to do exactly what you want.

[hrh1818 · Accepted solution]

A DIY suggestion for a 1 to 5 volt to 4 to 20 ma converter.

<http://www.edn.com/design/power-management/4371307/Convert-1-to-5V-signal-to-4-to-20-mA-output>

The circuit requires 3 precision resistors.  The cost of the circuit maybe reduced by using less precision resistors with some loss in accuracy.

hrh1818

[MMS79]

Thanks hrh1818,

In trial an error my I to P got some problem,

I replaced my I to P and now it is working absolutely fine.

Once again thanks

Regards

MMS79