Heck, Warren, I'll put it on the line :-). Use a very simple and cheap processor such as a Picaxe, pass the rs232 through it to Lady Heather etc, and capture the temperature, using it appropriately. Should work nicely and keeps the temp control local. Even put a little LED on it to indicate state. Don
WarrenS > TBolt Nuts > > To keep My TBolt's temperature constant so that the environment has > minimal effect on it, > I use an aquarium temperature controller (modified to have low hysteresis) > connected to a low wattage light bulb, placed in a box with the TBolt. > It works OK and keeps the TBolt's temperature constant to well under 1 > deg. > To do it better and make it more hi tech, > I'd like to have the temperature control based on the TBolt's internal > sensor. > > What I have found works well is to use the TBolt's own RS232 temperature > sensor output data, > and with a modified PID type of S/W controller, turn an external heater > &/or cooler on off. > > The heater can be an appropriate power resistor or transistor dissipating > up to about 4 Watt, > mounted to the TBolt case. What I use to cool the Tbolt up to 5 deg C, is > a small fan blowing > at a heatsink mounted on the top of the TBolt's case. > Turning the fan on & off with a S/W driven switch, can be used to keep the > TBolt's > internal temperature very constant over a limited external temperature > range. > A standard PC chip fan & heatsink may be OK, if it does not add Phase > noise due to it's vibration. > > Because of the long time constant and slow response of the internal > temperature sensor, > a single digital on-off bit, updated at a max rate of once per second > works great for control, > No analog needed. To keep the hardware and interface circuit simple, > I'd like to be able to use one of the unused standard RS232 outputs, > such as RTS, CTS, DSR, DTR as the heater/cooler control bit(s). > This is no problem when doing this in a DOS program or from an added > microprocessor > that monitors the Tbolt's communications, But the question is, > can it be done in Windows in such a way that a modified existing program > such as > Lady Heather or Tbolt monitor could control an already existing readily > available digital bit? > > Being a control person, Doing a software algorithm is the easy part. > Making Windows do any kind of non standard I/O control, is way above my > capability. > I'd like to get feedback from a Windows expert if there is a simple way to > control an existing Digital bit > that would be available on a PC being used in a typical setup that is used > to monitor the Tbolt. > One way I have heard suggested is to use the sound card output, > but I'd like to keep it even simpler than that, Any suggestions? > > If anyone is interested in developing a program to make an existing stand > alone micro > or basic stamp to include this function they can contact me off line for > some sugestions. > > Thanks, > ws > ****************** > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.