mosfet help

I have been told I need to use a mosfet to get this working with my arduino as it is controlled with 2-10v http://uk.farnell.com/jsp/search/productdetail.jsp?CMP=cmwis_email&sku=1936419 I am new to electronics and would be grateful if any one could post a schematic to allow the arduino pwm pin to control this bit of kit, also a link to the farnell site to which mosfet to buy as there are so many different types. I understand I need a logic type. Any help would be appreciated.

You were misinformed. All that it requires is a digital output pin, 0/5V.

*** The "2-10V" means that it's good with a minimum of 0/2V and as much as 0/10V. So controlling it with 0/5V is a winner. ***

Are you sure, looking at the data sheet it says this prportional controller will only give 50% power at 5v and 100% at 10v. Or am i reading it totally wrong.

The link you provided is for a solid-state relay.
Its input is 2-10VDC, its output is rated for 240vac.
It’s “on” when its input is anywhere between 2 and 10V; it’s “off” when its input is 0V.

no it is a proportional controller here is a link to the data sheet. http://www.crydom.com/en/Products/Catalog/p_cv.pdf

OK The link calls it an SSR, but its datasheet has it as a proportional controller. So, it's different.

So, you want/need a means of 0/5V (PWM?) to 0 to 10V variable?

yes please

runaway_pancake:
OK
The link calls it an SSR, but its datasheet has it as a proportional controller.
So, it’s different.

I think it is a proportional ssr

I wonder if a PWM'ed 0/10V would suffice or if it requires a nice, smooth, 'constant' (within range) DC control voltage.

runaway_pancake: I wonder if a PWM'ed 0/10V would suffice or if it requires a nice, smooth, 'constant' (within range) DC control voltage.

im not sure, the data sheet just gives d\c voltage to power charts

It'd be easy enough to switch (PWM) a transistor, and therefore the controller's input, between 0 and 10V, especially since it's just LED current there. Smoothing the Arduino PWM (approx 430Hz ?) with a low-pass filter and an op-amp and then amplifying the result (X2) would be more complicated, but hardly impossible.

runaway_pancake: It'd be easy enough to switch (PWM) a transistor, and therefore the controller's input, between 0 and 10V, especially since it's just LED current there. Smoothing the Arduino PWM (approx 430Hz ?) with a low-pass filter and an op-amp and then amplifying the result (X2) would be more complicated, but hardly impossible.

can I have the easy option please as the other has gone straight over my head.

OK.
Attached is a drawing for the first (easiest) option.
The transistor is just a “garden variety” NPN.

*** “Ordinary” SSRs need a load on the output - without a load the output will always show high-voltage (assuming use of a modern DVM) regardless the control state. ***

pcsw.JPG

runaway_pancake: OK. Attached is a drawing for the first (easiest) option. The transistor is just a "garden variety" NPN.

*** "Ordinary" SSRs need a load on the output - without a load the output will always show high-voltage (assuming use of a modern DVM) regardless the control state. ***

Excuse me for being a bit thick but is that a battery on the schematic?

"That"? It's a representation of the SSR/module, emphasis on its input terminals.

"Woe is me for I am undone."

Thanks ill give it a try

I just setup this circuit and the pwm from the arduino is putting the correct voltages to the controller, but when I put a 100w lamp through the load of the controller it does not dim when I change the settings to the pwm pin. If i make the pin value 255 the lamp is on full brightness but when I go to any lower value the lamp seems to flash on and off very fast. also when I put my meter across the 2-10v terminals when there is load on the output the polarity reverses.

I was wondering how that'd work. I think the PWM freq and the mains freq are mixing. Don't know about that "polarity reversal". If it's hooked up right then there's nothing to reverse. The 12V supply's ground and the arduino ground and the transistor ground are all in common (connected together)?

So, then, you need a clean, stable DC source for the control volts. Like I mentioned last week, that could be based on filtering the PWM. If you can devote several arduino output pins, you could effect a "crude" DAC [ http://www.asdlib.org/onlineArticles/elabware/Scheeline_ADC/ADC_DAC_ladder.html ]. You could buy a DAC IC and run that from the arduino.

You don't need 60V, but... http://www.arduino.cc/playground/Main/RegulatedPositiveVoltageBooster

http://digital-diy.com/swordfish-example/314-digital-to-analogue-conversion-dac-via-pwm.html