building application to detect thyristor effect in diode

leesing2k3 · Joined: 08 Nov 2005 Posts: 28

i am building an application to detect thyristor effect in a diode. in order to do so, a current from 0mA to 50mA need to be sourced to the diode to detect the thyristor effect.

So, i get AD558 to source a voltage from 0 to 10V and hope that i can use a resistor to control the current. But, AD558 is only able to source around 15mA.

Is there anyway that i can linearly amplify the current from 0 to 50mA? Resistor? Opamp?

Thanks in advance.

adrian · Joined: 08 Sep 2003 Posts: 92 Location: Glasgow, UK

What you need is something like this
http://pdfserv.maxim-ic.com/en/an/A0912.pdf

leesing2k3 · Joined: 08 Nov 2005 Posts: 28

So basically I need an opamp to do the job?

jecottrell · Joined: 16 Jan 2005 Posts: 559 Location: Tucson, AZ

Google "programmable current source", "voltage to current converter", etc.

You can use a digital pot in a voltage divider to drive the source. (MCP41xxx part from Microchip is one option.)

That's just a start....

John