It is currently 28 Mar 2024, 11:52
Pete Maddex wrote:A double pole double throw switch would replace everything, and if you had a double pole double throw center off switch you could stop the motor at any point.
Pete
Pete Maddex wrote:I am sure a suitable spit boy could be procured from the street urchins in the local vilage....
Pete
Tiresias wrote:Maybe this sort of thing.
novocaine wrote:lots of analogue solutions, this still seems very much like the perfect use for a little microprocessor (Arduino style) and a pair of relays. a teeny limit switch to stop the motion and tell the brains to switch to the other direction next time (basically an if loop).
I promised to shut it though, so I'm going back in my cave.
John Brown wrote:That's what I said. You could even make it zero power when idle(well, FET leakage current only), since the limit switches effectively record the state.
novocaine wrote:John Brown wrote:That's what I said. You could even make it zero power when idle(well, FET leakage current only), since the limit switches effectively record the state.
Yep I saw tha, and it's what I said way back on page one, but I also knew what Mike would say, him being a bit "old school" and all that.
the current required to run such a simply program, I wouldn't be bothered by how much power it's using, it's going to cost something like a penny a year. more power lost to leakage than it would require.
John Brown wrote:I can't help it. Having done a lot of work on stuff expected to run forever on a CR2032, I automatically think like that. But also, I like the idea of a power on reset every time you press the button. Also probably unnecessary, but when I started doing this stuff, I worked with a chap who worried that the microprocessor would get bored and make mistakes if given am over simple repetitive task....
DaveL wrote:John Brown wrote:I can't help it. Having done a lot of work on stuff expected to run forever on a CR2032, I automatically think like that. But also, I like the idea of a power on reset every time you press the button. Also probably unnecessary, but when I started doing this stuff, I worked with a chap who worried that the microprocessor would get bored and make mistakes if given am over simple repetitive task....
I remember back in the 70's working on a processor based phone (for the Army) that used an 1802 processor, we were power fed over the phantom. They allowed us 2 watts, the final design came in at just under a watt.
It used to be common practice to have a watch dog timer on any real time processor controlled design. The processor would reset the timer once every pass round the main loop. If it hung due to a bad input signal or a bug the timer would expire and reboot the system.
I doubt we need a watch dog timer on Mikes TV lift.
John Brown wrote:.......it's all fairly irrelevant, as Mike wants a non electronic solution.
Mike G wrote:John Brown wrote:.......it's all fairly irrelevant, as Mike wants a non electronic solution.
Only because that's all I can do myself. If I had any better electronic skills or knowledge, I'd be happy for something more whizzy......
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