T&L Publications

At one time, some years ago you could buy remore car controls, complete with car and two way radio for something like $ 30 - $50 for from radio Shack, I'm sure they were quite crude and I have no idea how they worked but I'm sure you could take one to pieces and figure out how to adapt it to your ca...

Thank you all for the varied and interesting replies - which I enjoyed - I think that, as one or two posters said or implied, that nowadays almost anyone who is paid for some activity may claim to be a professiuonal in it. I'm 75 and I don't really know whether I'm retired or unemployed. If some out...

When you are using PID you need a setpoint (Desired Value ) and Process Variable (Measured Value) The error between them has to be represented as a proportion of some scale - What is your scale/s and how do you determine error magnitude with these (Sharp) sensors and an 8255 ? Don't you need some an...

Something is amiss here - I'm not really a phone man but I'm willing to learn by uttering wrong statements abd then being shot down - I believe that the exchange detects the 'Off Hook ' condition by detecting a current of 20mA or more in the lines ? I did not see the schematic but if you have a 2k2 ...

Ronh - You are, of course correct, it should have said Positive Temperature Co-Efficient I'm clearly too far gone to be trying to think while I write. As the famed Scottish Bard Robert Burns once was reputed to have said " Is it wise to remain silent and be thought a fool - Or to speak up and d...

All tungsten lamps possess negative temerature co-efficients i.e as they get hotter their resistsnce increases - just like a thermistor. So, you apply 110 volts which causes the lamp filament to heat up so that the resistance eventually balances with the voltage at some level which consumes approxim...

Re Age: It wouldn't help determination of my age to say which TV programs I first watched - I never got a TV until I got married They didn't exist before then. I do remember regularly watching German bombers, British fighters and Ack Ack guns overhead ( And fighting over whichever shards of shrapnel...

I thought I posted this yesterday - but it didn't seem to take - Again ! - I notice the several references to 'professional' in this section , with a few posters saying they were not one and no one caliming to be one - So, for amusement purposes only, here in the US - exactly what is a 'professional...

I believe all of the suggested solutions would work, in a fashion, none so far described are really practical because (1) In order to retain the high current output capability you need all of the max charging voltage for a twelve volt battery to go to 14 volts or more - consequently, when not in use...

Everyone is correct - this is a great board ! I was interested to see frequent use of the word 'professional' without anyone claiming to be one and several saying they were not one ? - I don't mean to start a war but I would like to know just what everyone thinks constitutes a 'professional' I think...

The formula in the reply I just posted should read V = Blv - NOT, as I mistakenly posted it as - B - Blv

Hi Greybie, I was just thinking about this very subject the other day and what I am going to do eventually is to make a coil, (The toilet paper former sounds like an excellent idea) fix it somewhere with the axis of the cylinder vertical then make a simple assembly from a fairly weak coil spring whi...

I once heard that, on average, for the purposes of sizing an air conditioning system, human bodies put out heat at the equivalent of seven human beings to 1.0 kiloWatt i.e, on average, a human being would put out about 143 Watts. As you were told by the previous correspondent, Volts are not units of...