Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

As far as the warm end of the temperature spectrum goes, I have used a Crockpot without the crock and put a thermometer probe inside. when I wanted it to stay at a specific temperature I threw a blanket over it and shut it off. I suspect you could get it to hold temperature better by simply

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

Hi Rick: I've used two types. 1. Most of the replies have been for controlled air temperature devices. These are by far the most common but also they take a long time to change temperature. 2. Hot/Cold plates are much faster since the DUT is in close contact with the plate. We used these with

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

It is amazing what is available for 10 - 20 dollars. Some of the LED drivers have a dimming input on the low voltage side. Not sure of the detailed implementation of a din temperature controller with 4-20 mA output, but it might be as simple as tl431 shunt reference and a resistor network to map

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

On 9/5/2016 9:48 PM, Richard (Rick) Karlquist wrote: > As we all know, step #1 in making a clock is NOT > to build a thermometer :-) > > I thought I would check the brain trust here to see > if anyone has seen a hobbyist grade temperature > testing chamber or kit or homebrew design. > Rick

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

Also avoids thermomechanical fatigue failure in the Peltier device. On Wednesday, 7 September 2016 12:14 AM, jimlux wrote: On 9/6/16 1:19 AM, Adrian Godwin wrote: > On Tue, Sep 6, 2016 at 4:24 AM, Bob Darlington > wrote: > >> Rick, >> >>

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

On 9/6/16 1:19 AM, Adrian Godwin wrote: On Tue, Sep 6, 2016 at 4:24 AM, Bob Darlington wrote: Rick, I'm going from memory here. My former business partner (now deceased) had a "beer fridge" setup as an environmental chamber for our instruments. The trick for

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

On Tue, Sep 6, 2016 at 4:24 AM, Bob Darlington wrote: > Rick, > > I'm going from memory here. My former business partner (now deceased) had > a "beer fridge" setup as an environmental chamber for our instruments. The > trick for stability was to run the AC compressor all

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

Constant temperature chambers are not hard to build. I assume you want stability in the range 0.001 to 0.01 degC. I have made a few of these chambers, about 1 cubic feet, out of 3/4 inch particle board, it is not a brilliant insulator, but you want some heat loss. Make a partition at one end with

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

There are cheap GC (gas chromatograph) ovens on eBay. They are well-insulated and give you fast, precise temperature control. Some of them are designed with a liquid nitrogen input for cooling. Otherwise, you can use dry ice. I saw one mentioned on one of the mailing lists I read, maybe

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

You don't need exact control of the temperature. You just need a slow rate of change and the ability to measure the temperature accurately. I have used a picnic cooler with some water in the bottom and a very small fish tank heater. But this was for an experiment in a home biology lab not an

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

Rick, I'm going from memory here. My former business partner (now deceased) had a "beer fridge" setup as an environmental chamber for our instruments. The trick for stability was to run the AC compressor all the time, and push against it with heat lamps. The lamps were controlled with an Omega

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

rich...@karlquist.com said: > I thought I would check the brain trust here to see if anyone has seen a > hobbyist grade temperature testing chamber or kit or homebrew design. I > have some crystals, oscillators, and other electronics I would like to > characterize over temperature. I know this

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

As with most things here - it depends. I have a converted wine cooler I use for some things. Bought it for $20 at a flea market. It had blow a fuse on the power supply. This appears to be a common failure. Won't handle much thermal load, but it's a Peltier unit, so it will heat as well if wired

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

On 9/5/16 8:52 PM, Scott Stobbe wrote: The bargain price mini coolers are often peltier cooled, they appear to fall under the marketing term "thermoelectric mini-fridge". I can't think of a project name, but I'm sure I've seen this done before using a mini fridge.

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

On 9/5/16 7:48 PM, Richard (Rick) Karlquist wrote: As we all know, step #1 in making a clock is NOT to build a thermometer :-) I thought I would check the brain trust here to see if anyone has seen a hobbyist grade temperature testing chamber or kit or homebrew design. I have some crystals,

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

The bargain price mini coolers are often peltier cooled, they appear to fall under the marketing term "thermoelectric mini-fridge". I can't think of a project name, but I'm sure I've seen this done before using a mini fridge. On Monday, 5 September 2016, Richard (Rick) Karlquist

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

Better stock up on 60W bulbs.  They are becoming outlawed. (Only kidding, a resistor works as well.) Also, a foam drink cooler will give a more stable temperature.  You can make it leak a bit of heat to get the thermostat to cycle.  The hard part is the thermostat; they aren't cheap - even the

Re: [time-nuts] Hobbyist grade or homebrew temperature testing chamber?

Yo Richard! On Mon, 5 Sep 2016 19:48:14 -0700 "Richard (Rick) Karlquist" wrote: > I thought I would check the brain trust here to see > if anyone has seen a hobbyist grade temperature > testing chamber or kit or homebrew design. When I did this for testing labs, I took a

[time-nuts] Hobbyist grade or homebrew temperature testing chamber?

As we all know, step #1 in making a clock is NOT to build a thermometer :-) I thought I would check the brain trust here to see if anyone has seen a hobbyist grade temperature testing chamber or kit or homebrew design. I have some crystals, oscillators, and other electronics I would like to