I'll preface this with I'm a computer scientist not an engineer. So feel free to correct away. I'll never learn if you don't.
I'm trying to work out a simple control for creating small temperature changes on an aluminum surface +/- 0.1C/sec to +/- 0.4C/sec. The peltier looked like a good fit for the device so I've ordered two 7w 20mm peltiers online to mess around with.
I've been looking around for simple ICs to control the TEC and I'm hunting around bi-directional motor controllers using H-Bridges. So my question is, given the ratings of the peltier, what specs should I look for in the chip or dip?
Here are the specs on the TEC:
Type: TEC1-04902
10W
Couples: 49
Imax (A): 2
Vmax (V): 5 (usually working <=5v)
QCmax (W):7
Dimensions: about 20 x 20 x 4mm
Tmax △C: 67
I read that the optimum current for a peltier is around 75% of the Imax, so I would think that means I should use a supply of 1.5A at around 4.5V (6.75 watts), is that even right?
The problem I run into is finding an IC that does that. The closest I have come that looks simple to work with is TI's L293 which outputs from 4.5V to 36V and 1A per channel.
If I were to supply 4.5V at 1A to the chip to drive the Peltier would that still work for my application?
My second problem is I need to regulate the temperature of the surface with a decently rapid response time. Is measuring off a LM35 and using the result to regulate PWM on the peltier via the L293NE a good fit? Will all the rapid temperature changes (albeit small) junk my peltier too quickly?
I'm trying to work out a simple control for creating small temperature changes on an aluminum surface +/- 0.1C/sec to +/- 0.4C/sec. The peltier looked like a good fit for the device so I've ordered two 7w 20mm peltiers online to mess around with.
I've been looking around for simple ICs to control the TEC and I'm hunting around bi-directional motor controllers using H-Bridges. So my question is, given the ratings of the peltier, what specs should I look for in the chip or dip?
Here are the specs on the TEC:
Type: TEC1-04902
10W
Couples: 49
Imax (A): 2
Vmax (V): 5 (usually working <=5v)
QCmax (W):7
Dimensions: about 20 x 20 x 4mm
Tmax △C: 67
I read that the optimum current for a peltier is around 75% of the Imax, so I would think that means I should use a supply of 1.5A at around 4.5V (6.75 watts), is that even right?
The problem I run into is finding an IC that does that. The closest I have come that looks simple to work with is TI's L293 which outputs from 4.5V to 36V and 1A per channel.
If I were to supply 4.5V at 1A to the chip to drive the Peltier would that still work for my application?
My second problem is I need to regulate the temperature of the surface with a decently rapid response time. Is measuring off a LM35 and using the result to regulate PWM on the peltier via the L293NE a good fit? Will all the rapid temperature changes (albeit small) junk my peltier too quickly?