Use a momentary / tactile button, as a latching switch - circuit?

[rhd]

Inefficient as using an array of toasters to heat your house, but it works perfectly well.

Incidentally, toasters are 100% efficient

But only if you live in a basement apartment with no glass windows for the photons from the glowing toaster element to escape through

 

[Sigurthr]

In such an application it is mostly convection currents that would carry the heat from the elements, and since they are closed bottom there wouldn't be much of an airflow rate leading to inefficient heat transfer from the elements to the air and surroundings. That's the main point I ineffectively alluded to in the first post, heh.

Electrically, all heating devices with a power factor of 1 are 100% efficient. In fact, in a cold house you intend to heat, all electrical devices with high power factors are highly efficient, whether they are intended as heaters or not. The switch from incandescent lighting, which has an electricity to light efficiency of about 3%, to modern "efficient" lighting causes an increase in heating bills during cold weather.

 

[rhd]

I finally have an excuse for leaving all the lights on

Actually, despite living in Canada, I haven't turned my heat on yet this winter (and it's March now, so I doubt this will change).

Not to derail the efficiency conversation, but it occurred to me that someone asked why I wanted / needed this circuit, and I didn't answer.

The truth is, I don't actually have a current use for the circuit. However, after a few years away from lights / lasers, I've been playing catch-up grabbing some of the new hosts out there. I've noticed a trend towards hosts that use momentary switches / tactile buttons. It's either a trend, or just a reflection of the type of hosts that have caught my attention recently. Either way, it seems like there is a growing body of hosts with buttons/switches that will be challenging to use as laser hosts, absent a circuit like this.

That was my objective - to get something out there, quickly, that can be dropped in-stream with existing drivers, to make this new wave of hosts that use low-current monetary switches, laser-friendly.

The circuit / board files will be made open source once I've verified that the design works (if anybody really wants them now, I'm happy to send you them by PM). That's the explanation - not super exciting I'm afraid.

 

[Sigurthr]

This house is poorly insulated and has an ineffective propane-water heater system that pumps 140F water through baseboard radiators. We've been burning $550-750/month on propane costs alone trying to keep the house above 60F. If it were my house I'd have switched to wood fire or electric on demand room heaters years ago but I'm not the landlord here, just the maintenance man. I did the math and tested it out by shutting off the propane system; it costs about $3/day to keep occupied rooms at 72F with electric heat, but on average $20/day to heat the whole house to 60F using propane. Still, the landlord won't switch over because it makes her purchase if the propane system out to be a lemon.

I like e-switches because you can switch high voltages and currents without the switch bearing the load.

 

[djQUAN]

I like e-switches because you can switch high voltages and currents without the switch bearing the load.

And without the hassle of intermittent dirty contacts that later burn out due to overheating.

 

[Wolfman29]

I finally have an excuse for leaving all the lights on

Actually, despite living in Canada, I haven't turned my heat on yet this winter (and it's March now, so I doubt this will change).

Not to derail the efficiency conversation, but it occurred to me that someone asked why I wanted / needed this circuit, and I didn't answer.

The truth is, I don't actually have a current use for the circuit. However, after a few years away from lights / lasers, I've been playing catch-up grabbing some of the new hosts out there. I've noticed a trend towards hosts that use momentary switches / tactile buttons. It's either a trend, or just a reflection of the type of hosts that have caught my attention recently. Either way, it seems like there is a growing body of hosts with buttons/switches that will be challenging to use as laser hosts, absent a circuit like this.

That was my objective - to get something out there, quickly, that can be dropped in-stream with existing drivers, to make this new wave of hosts that use low-current monetary switches, laser-friendly.

The circuit / board files will be made open source once I've verified that the design works (if anybody really wants them now, I'm happy to send you them by PM). That's the explanation - not super exciting I'm afraid.

That's as good an explanation as I wanted! The only problem I foresee with devices like this is that they will have to fit in the switch holder, not near the driver because most driver pills are press fit, i.e. have no spare room :\

 

[rhd]

Reflowed one of these tonight. The latch worked great. However, the latch release (ie the second press) didn't work, it just stays on.

However, I didn't have 1M resistors, so all resistors used were 100k. This may have been the problem.

 

[Sigurthr]

Could very well have been the resistor swap that did it. I hate trying to troubleshoot bipolar circuits. (incorrect base currents are SO much harder to diagnose than incorrect gate voltages!)