10VDC power supply

[DGR 0]

I am wanting to experiment with the analog inputs of my ML 1100 but am having trouble finding a 10vdc power supply. Any suggestions?

[Guest trn_psycho]

Errr... How about using a 12V supply, a 10V zener diod, and a pot...

[DGR 0]

I want to monitor a 1k linear xducer. I was going to use a voltage divider with resistors but the xducer across the load alters the thevenin's resistance. Will the diode prevent this?

[panic mode 246]

two 5V supplies...?

[Guest trn_psycho]

Pardon... I just re-read your post... Do you have the xducer to play with? If so, and you're just looking for a supply to power it (10V), then all you need is the 12V supply and the diode. When you reverse bias the zDiode, you'll be able to use it as your 10V supply. That way, you wont even need to worry about building a voltage divider...

[DGR 0]

I'll give it a try. Thanks.

[panic mode 246]

can you explain this a bit more? i don't follow because zener diodes ARE used reversebiased and need resistor for such operation. when forward biased, they are just like regular diodes (drop some 0.6V when in series with load). I'm not aware of transducer that would require 10V for operation but when using potentiometers this is different story. depending on required accuracy, this source may have to be dedicated regulated supply. if accuracy is not critical (like experimenting) one can simply add series resistor in series with the pot and simply connect to 24V. usual combination is 1K for pot and 1.5k for series resistor but values are not critical as long as ratio is correct and pot resistance is significantly lower than that of analog input.

[Guest trn_psycho]

I stand corrected... You do need to have a resistor in the circuit to get the correct voltage drop. There are tons of references on the Net about how to make a zener voltage supply. Are you sure that the xducer wants 10V for its' supply power? Normally this would be 24V or 110V for the input (power required) with an output of +-10V or 4-20mA (maybe 0-10V for some systems.) Oh, and I'm not sure where I got 12V from... I meant 24V... Edited 28 Sep 2006 by trn_psycho

[DGR 0]

The xducer CAN take 24vdc, however, the analog input can only take 10vdc. The wiper resistance of the xducer is in series with the analog input resistance. The analog input resistance is around 200k. This means that the input is going to drop most of the 24vdc. As the xducer travels the wiper resistance of it approaches zero causing all the 24vdc to drop across the analog input. I had a low power zener so I used a voltage divider along with it and it appears to be working nicely.

[jjordan 0]

I bought a Current and voltage calibrator from EXTECH. Battery operated, works great for a current or voltage source to test/set-up analog channels. or simulate a process instriment (sp). The batterys go south if you leave it on to long but works great. Around 200 USD. http://www.omnicontrols.biz/merchantadmin/...sp?subcatid=119 Edited 29 Sep 2006 by jjordan