MCS water tank gauge electricity consumption

[SamKingfisher]

Hi. I can't seem to find an answer from Google. What does the needle gauge mcs water tank job use? I presume some fraction of a watt, but want to make sure as I have the option of fitting a momentary switch to the housing.

 

Nice piece of kit so far btw.

[Bobbybass]

Mine was so small..it didn't register on anything...

 

It was on all the time and there was no appreciable loss of power. I wouldn't bother with a switch.

 

It's based on the LM741 op-amp whos power dispation is 500Mw..but in the water level situation it doesn't consume anywhere near that as it just constantly drives a meter.

 

I did 'meter' it once..it showed 60Mw but then my meter was inaccurate at that level. That was with a full tank..but the power drops off as the tank gets lower.

Edited January 10, 2015 by Bobbybass

[SamKingfisher]

Thanks Bobby. I'll leave the switch. I wouldn't have considered it at all except for seeing one in a camper just the other day.

[bottle]

I've got four of them all running continuously, do you think they will flatten my batteries.

 

 

 

 

 

 

 

Just ignore:

[cuthound]

 

I did 'meter' it once..it showed 60Mw

60 megawatts, that must have really caned the batteries

[Bobbybass]

60 megawatts, that must have really caned the batteries

 

Millipedes !!

 

I 'recall' that it had a single LM741...as I once blew it out.

 

This was on the Thames..where there was a 'provided hose'. The hose was large diameter and made a seal around the filling point. As such...when I turned on the tap...the pressure was such that it blew the 'chip'. I fitted an IC holder so I could insert another if it did it again..and bought some extra LM741's on Ebay (about 20p each ).....but never had to do that..as I learned my lesson !

[by'eck]

I have my gauges (fuel and water) on a switch but the circuit provides gauge illumination as well.

[ditchcrawler]

I once contacted them about putting in a switch and running it off a dry cell battery to save running a supply to it. The answer was just conect it to the dry cell battery as the current was so low it would last for ages powered all the time.

[dmr]

Mine was so small..it didn't register on anything...

 

It was on all the time and there was no appreciable loss of power. I wouldn't bother with a switch.

 

It's based on the LM741 op-amp whos power dispation is 500Mw..but in the water level situation it doesn't consume anywhere near that as it just constantly drives a meter.

 

I did 'meter' it once..it showed 60Mw but then my meter was inaccurate at that level. That was with a full tank..but the power drops off as the tank gets lower.

 

I am maybe having an electronic geek moment here but I suspect the 500mW is the maximum dissipation allowed before it blows up, not what it uses in normal service. I think its quiescent current is a couple of milliamps. The sensor and other components may use a bit too.

If the op really wants to save power then cleaning the tops of the batteries very day may be a better bet than switching off the water meter!!!!

 

..............Dave

[AndrewIC]

Just put the meter on the supply to mine: 10.8mA at a scale reading of 4/10 tank, same at 0/10. 14.25V supply voltage (engine was running!)

[Pykebird]

I have put a switch on mine so I can turn off the pump if needed. But I must remember to turn it back on before I panic that I have used 3 weeks worth of water in a day!! The gauge reads zero when not switched on.

Edited January 11, 2015 by pykebird

[SamKingfisher]

Just put the meter on the supply to mine: 10.8mA at a scale reading of 4/10 tank, same at 0/10. 14.25V supply voltage (engine was running!)

This might not seem like loads to you lot, but I have only a 95mA alternator. Joke. No really, it is on the rat's exercise wheel.

 

I did leave a needle gauge switched on for the starter battery once and it didn't start up with the usual gusto. I think it was down to 12.4 when I spotted it.

[ditchcrawler]

This might not seem like loads to you lot, but I have only a 95mA alternator. Joke. No really, it is on the rat's exercise wheel.

 

I did leave a needle gauge switched on for the starter battery once and it didn't start up with the usual gusto. I think it was down to 12.4 when I spotted it.

But what else did that switch you left on feed.

[SamKingfisher]

It's just a needle gauge with a 3 way switch, leisure/off/starter.

My starter battery feeds this gauge or starts the engine. Oh and the immersion element I use to warm the cut for my morning dip.