Converting 0-5V to 4-20mA using a Howland Current Pump for Scientists

  • Thread starter Thread starter DaineAtkins
  • Start date Start date
  • Tags Tags
    Industry Standard
AI Thread Summary
The discussion focuses on converting a 0-5V signal to a 4-20mA output using a Howland Current Pump. Users share resources, including a National Semiconductor app note that provides both basic and detailed analyses of the Howland Current Pump. The original poster seeks assistance with circuit design and methodology, specifically mentioning the need for a 0-20mA output from a 5V input. Suggestions include using a 250-ohm resistor for low impedance applications. The conversation emphasizes the need for schematic sharing to facilitate further help.
DaineAtkins
Messages
3
Reaction score
0
I have a 0-5V signal which I need to convert 4-20mA by using a Howland Current pump.
I know that there are more steps to the whole process but I have misplaced all my notes that I originally had. Could someone please help?
 
Engineering news on Phys.org
Welcome to Physics Forums!

I fully admit that I've never heard of (or at least don't remember) the Howland Current Pump. However, the first Google Thing that comes up when Googling for Howland Current Pump:
http://www.google.ca/search?q=howland+current+pump

...is an app note from National Semiconductor entitled "A Comprehensive Study of the Howland Current Pump". Quickly perusing it, it seems to present a basic inspection analysis as well as a more detailed mathematical analysis (for both basic and improved variants).

Does this help?
 
The Howland Current Pump doesn't seem to be working properly.
Basically, I need to convert a 0-5V signal to 0-20mA
and a 1-5V signal to 4-20mA.
If anyone could please help me a.s.a.p!
 
Can you post your schematic, and your test methodology / results? Or are you asking us to design your circuit for you?

While we can't do the latter, we might be able to help you with the former.

If you're not worried about output impedance / voltage levels, and have (very) low input impedance (e.g. op-amp driven output driving an analog current meter) you could just use a 250 ohm resistor.
 
I am using a LM741 with an input of 5V and I need a 0-20mA output with a 250ohm load
I know that the saturation voltage of the op-amp is +/- 13V. I have calculated my design using a compliance voltage of 5V.
How do I post my schematic?
 

Thread 'Underwater piezoelectric sensor array receive sensitivity'

Hi all I have some confusion about piezoelectrical sensors combination. If i have three acoustic piezoelectrical sensors (with same receive sensitivity in dB ref V/1uPa) placed at specific distance, these sensors receive acoustic signal from a sound source placed at far field distance (Plane Wave) and from broadside. I receive output of these sensors through individual preamplifiers, add them through hardware like summer circuit adder or in software after digitization and in this way got an...
View full post »

Thread 'Following up on the recent thread about Earth Resistance measurements'

I have recently moved into a new (rather ancient) house and had a few trips of my Residual Current breaker. I dug out my old Socket tester which tell me the three pins are correct. But then the Red warning light tells me my socket(s) fail the loop test. I never had this before but my last house had an overhead supply with no Earth from the company. The tester said "get this checked" and the man said the (high but not ridiculous) earth resistance was acceptable. I stuck a new copper earth...
View full post »
Thread 'Beauty of old electrical and measuring things, etc.'

Thread 'Beauty of old electrical and measuring things, etc.'

Even as a kid, I saw beauty in old devices. That made me want to understand how they worked. I had lots of old things that I keep and now reviving. Old things need to work to see the beauty. Here's what I've done so far. Two views of the gadgets shelves and my small work space: Here's a close up look at the meters, gauges and other measuring things: This is what I think of as surface-mount electrical components and wiring. The components are very old and shows how...
View full post »

Similar threads

Output 0-20mA from an Arduino with ATMega328
Replies
5
Views
9K
Convert 1-5V to 4-20mA: Which op-amp ?
Replies
11
Views
14K
LED's in Series Vs LED's in Parallel
Replies
25
Views
8K
Understanding the 4-20mA Standard in Industrial Control Systems
Replies
8
Views
13K
Protection on Step up and Step Down Converter Module Bucks
Replies
1
Views
2K
Can I series buck converters to get higher stepdown ratio?
Replies
10
Views
2K
Impact of Current loading for voltage multiplier
Replies
1
Views
2K
Help with understanding of RF theory-Kinetic inductance parametric amp
Replies
1
Views
2K
Calibrating Pump/Venturi (Air) in a Closed Recirculating Water System
Replies
1
Views
379
What is the Type of Laser Used in My Wine Raman Spectrometer?
Replies
7
Views
2K

Hot Threads

Recent Insights

Back
Top