Hi, I am a student. I have a low basic in electronics and circuits,
I need some help for making a circuit to control temperature of a heater cartridge.
I have the following things
Cartridge heater Voltage: 12V power 40W
Thermistor:NTC 100K B=3950
I want to control temperature using NI USB 6211
Please help me making the circuit and wiring. If i need to buy any thing please suggest me.

 

I have a thermistor thermostat laying around, but the USB I don't. Here's a datasheet for the requested interface:

 

I have a thermistor thermostat laying around, but the USB I don't. Here's a datasheet for the requested interface:

I want help regarding wiring and making circuits. For circuit should I buy anything like Relay/ MOSFET. I have just got some ideas but not sufficient.

 

So, what's the deal here? You want to start with, "How to solder" and make your first project a USB controlled heater?
Have you heard about Ohm's Law? Watt's Law? Have you ever designed any circuit?

ps, here's the thermostat. You will have to change some resistors to make it compatible with a 100K thermistor.
http://forum.allaboutcircuits.com/blog/lm723-as-a-thermostat.532/

 

Your circuit could be based on something like this :-

 

Your circuit could be based on something like this :-
View attachment 111665

Hi Alec_t,
Thanks a lot for your reply.
Plese clarify me the following things, in USB6211 you have shown A & D here A= ANALOG INPUT
D= DIGITAL OUTPUT/PWM right???
2. +5V will come from USB 6211 right??
3. what is Trim?
4. There are 3 pins for N- MOSFET. Gate, Source and Drain
Please elaborately tell me only about these 3 pins connections.
5. will you suggest me which N- MOSFET will be suitable for my application?? is there any model number?

 

Hi Alec_t,
Thanks a lot for your reply.
Plese clarify me the following things, in USB6211 you have shown A & D here A= ANALOG INPUT
D= DIGITAL OUTPUT/PWM right???
2. +5V will come from USB 6211 right??
3. what is Trim?
4. There are 3 pins for N- MOSFET. Gate, Source and Drain
Please elaborately tell me only about these 3 pins connections.
5. will you suggest me which N- MOSFET will be suitable for my application?? is there any model number?

6. Another thing I want to keep the temperature constant at 200C. For this one should I need anything more??

 

A= ANALOG INPUT
D= DIGITAL OUTPUT/PWM right???

Right.

+5V will come from USB 6211 right??

No. From the USB bus. According to the datasheet the USB6211 is "bus-powered".

what is Trim?

A trimmer potentiometer wired as a rheostat, to allow setting of the input operating point if need be.

There are 3 pins for N- MOSFET. Gate, Source and Drain

Yes. The pinout depends on the particular FET you choose/ can obtain where you live.

will you suggest me which N- MOSFET

Don't know your component source. Do you buy locally or on-line? Can you access Farnell, Digikey, Mouser, .....?

 

Another thing I want to keep the temperature constant at 200C. For this one should I need anything more?

You may do. Depends on what you are heating, how accurate the temp must be, how fast the system must respond to thermal transients, etc. A PID controller (Google will explain) may be required.

 

Right.

No. From the USB bus. According to the datasheet the USB6211 is "bus-powered".

A trimmer potentiometer wired as a rheostat, to allow setting of the input operating point if need be.

Yes. The pinout depends on the particular FET you choose/ can obtain where you live.

Don't know your component source. Do you buy locally or on-line? Can you access Farnell, Digikey, Mouser, .....?

I buy from the both of the sources that means locally/ online. I can access DIGIKEY.

 

Here are 652 mosfets starting at 56 cents, that will probably do the job.
http://www.mouser.com/Semiconductor...aong1SGgjdhp2Z1yw6zslZ1yw768lSGT&Ns=Pricing|0