• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 29 subscribers
  • Views 1567 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

DRV8873: Using H-bridge driver for controlling Thermo Electric Coolers, TECs (aka Peltier heating / cooling elements)

DRV8812: High power TEC controller

Chris van der Aar
Intellectual 570 points
Part Number: DRV8812
Other Parts Discussed in Thread: DRV8832, DRV8412

Fur a new project for one of our customers we need to control a climate chamber by a Peltier module. Probably we will need a module with at least 100W cooling capacity (+24V module).

I found the DRV8812 or DRV8832 that should be suitable to control such modules and I found an application sheet for a TEC driver in your datasheet. However some questions about this :

1) Is it possible to reverse the voltage at the TEC with this module because we need to cool down and heat up. Or do we need additional electronics when we want to reverse the Peltier current?

2) I found different applications and comparisons between PWM and linear control (direct current) where the PWM control is very inefficient compared with linear control. So I was wondering if t.I has examples of linear control of a TEC. Or do you think the efficiency  with a DRV8812 (or DRV8832) is quite well?

3) Do you know if there are standard controller chips for controlling the DRV8812 or is it possible to control this directly from an embedded PC (e.g. with I2C or SPI PWM controller)

Regards

Chris van der Aar

NTS Systems Development

Eindhoven, The Netherlands

  • 0
    TI__Guru 56650 points

    Chris,

    1. DRV8812 and DRV8832 both can reverse the voltage at the TEC. Check the table 1 in both datasheets.

    2. Please forward me the comparisons. I would think PWM control has the high efficiency for the whole system.

    3. DRV8812 and DRV8832 use hardware pin control interface and doesn't support I2C or SPI control. On our EVM, we used MS430 as the MCU. In your application, you can use other low cost MCU to control DRV8812 or DRV8832 inputs.

  • 0 in reply to Wang5577
    Intellectual 570 points

    See below a comparison from a supplier of TEC controllers where they compare PWM and SMPS control so I was wondering about efficiency when we would use the DRV8812 or DRV8832 (with PWM) as controller for the type of Peltier Element we are going to use (probably +24V/113W with 5.8A running current and 6.8A startup current).

    Furthermore this application note from T.I. shows a comparison with PWM and constant current control of TEC with the following conclusion (but is more related to low power TEC drivers):

    http://www.ti.com/lit/an/slua979a/slua979a.pdf

    Conclusion
    This application report shows that with a reasonable amount of power budget (2.5 V at 1 A, 2.5 W), even though the Peltier is not cooling anything, significant temperature differences were obtained, which can be interesting in some applications. Moreover, constant current drive is definitively preferred over PWM drive. If the design requires the ability to reverse polarity, the full bridge is the most flexible option but it significantly reduces the efficiency

  • 0 in reply to Chris van der Aar
    Intellectual 570 points

    Sorry I was wrong about the part number. I meant the DRV8412 and DRV8432 as TEC driver for high current (because we need around 6A @24V). The datasheet shows an application with this driver and I was wondering if we can reverse the current (heating and cooling) for the TEC and about the efficiency when using this driver with these high currents.

  • 0 in reply to Chris van der Aar
    TI__Guru 56650 points

    Chris,

    Yes.  DRV84x2 can reverse the current (heating and cooling) for the TEC and about the efficiency when using this driver with these high currents.

    Please check datasheet "7.2 Functional Block Diagram", with different PWM_x signal, we can control the current direction.

    In the efficiency comparison, it doesn't mention how to use a DC supply to generate a DC source. That could be a PWM controller and loss could be there. If total heat 59W vs 14W is true, I would go 14W solution.