Heater recommendations for a small fixture

I am trying to build a fixture to heat a 1"x3" metal plate in the range of room temp to ~ 70 deg C with a resolution of 0.5 deg C. I looked into PTC and Peltier options, and was looking for recommendations (. Also, for control, are there any programmable controllers I can look into?
PS: Stretch goal. Can I use the Peltier to heat and cool the fixture or would need a two step setup.


70°C is within the maximum operating temperature range of many available peltier modules, and they can indeed function as very efficient heating elements. They’re wretchedly inefficient at cooling however, but still find limited use for such purposes as a result of being small, light, and easily controlled to a high degree of precision. If you don’t feel like stretching, a heating element such as DK0103SA wouldn’t require a heatsink/fan and would be much less hassle.

There are products such as the TC-XX-PR-59 available that are designed specifically for driving peltier devices in a bi-directional fashion. User manual for that should be here. Others are available that only control in one direction and in less sophisticated fashion are available at lower cost.

Since temperature control is a routine industrial task, there are also a lot of modules designed to perform the control function. These provide low-level control outputs in response to sensor inputs, so one must separately provide an appropriate means of switching power for the driven device.

Especially if one is attempting to perform some purposeful cooling using a thermoelectric/peltier module, it is strongly recommended to read up on the basics of heat transfer, thermal modeling, and application of these devices. I can’t recall a single instance where somebody skipped the math and succeeded in their objective using the “just try it” approach. Some posts that might be useful to this end are listed below.