Dummy Load

[dmr]

1 minute ago, Loddon said:

That's a cool idea I think I will go down a similar route.

Its probably a bit over the top for boating but I still do a little bit of work that needs me to check calibrations, and its not much money.  Have just got a meter for measuring the moisture content in our firewood. I like measuring things ?

 

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

[Chewbacka]

3 hours ago, Loddon said:

Both meters are cheap chinese digital shunt jobbies accuracy is quoted as 1% +/- 2 word

One thing I have just thought of is that I only have one shunt here as the other is in circuit on the boat  so both will be calibrated to the one I have here

Knowing my luck the shunts will be slightly out but at least I will know and so long as I use the shunt that was used for calibration on the domestics I will never see a difference as two meters are on the domestic shunt with one switchable between domestic and start.

I am ignoring the fact that one meter will have 8m of cable on it and the other 1m hoping that their impedance is high enough to negate any voltage drop

 

 

You can also measure the voltage across the shunt whilst under load with your voltmeter that you are happy with.  Then calculate the current from the voltage and see how close your current meters are to that.  The shunt ‘calibration’ is probably stamped on the side.

[Tracy D'arth]

Not being funny or sarcastic at all, I'm interested, what do you do in your other life? I am OCD about a few things so I do understand.

I have never met any item on a boat that has to be so accurate that 3 meters are required, pray tell me why?

[GUMPY]

15 minutes ago, dmr said:

Its probably a bit over the top for boating but I still do a little bit of work that needs me to check calibrations, and its not much money.  Have just got a meter for measuring the moisture content in our firewood. I like measuring things ?

 

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

Test equipment I still have:

Fluke 8062A true RMS meter

UNI-T UT203 DVM

another cheap DVM

Megger CBT3 RCD tester

Bosch DMF10 cable finder

ISO-TECH IIT2302 insulation/continuity tester

Laser distance measure

Infra red pointy thermometer

Moisture meter (used once a year to check caravan)

Another Fluke I cant find

 

I was looking at a 3amp bench psu today to replace one I built 25 years ago but I don't really need it.

In fact I don't really need most of the above but I am a sucker for test gear and tools.

The only thing I don't have anymore is a scope as when I gave up work I was offered silly money for mine so I let it go.

[GUMPY]

12 minutes ago, Tracy D'arth said:

Not being funny or sarcastic at all, I'm interested, what do you do in your other life? I am OCD about a few things so I do understand.

I have never met any item on a boat that has to be so accurate that 3 meters are required, pray tell me why?

I assume you mean the current meters

1: one in the engine space

2: one in the area where the solar control, smartgauge, heating controls etc are which is on the accomodation side of the cross bed.

3: a portable one for use anywhere

The reasons for the two new meters (1 and 2) is 

1: I am lazy and don't like getting the clamp meter out

2: I am lazy and don't like climbing across the cross bed to check voltage/current.

 

I am thinking of extending the USB cable on my Victron so I don't have to climb over the cross bed or better still go Bluetooth

 

As for having 3 DVM that's a hangover from work

 

Edited October 1, 2020 by Loddon

[dmr]

29 minutes ago, Loddon said:

Test equipment I still have:

Fluke 8062A true RMS meter

UNI-T UT203 DVM

another cheap DVM

Megger CBT3 RCD tester

Bosch DMF10 cable finder

ISO-TECH IIT2302 insulation/continuity tester

Laser distance measure

Infra red pointy thermometer

Moisture meter (used once a year to check caravan)

Another Fluke I cant find

 

I was looking at a 3amp bench psu today to replace one I built 25 years ago but I don't really need it.

In fact I don't really need most of the above but I am a sucker for test gear and tools.

The only thing I don't have anymore is a scope as when I gave up work I was offered silly money for mine so I let it go.

You can get a half decent chinese 'scope with a colour LCD screen for not too much money, especially if you are happy not to go above about 20MHz, I know they are not as nice to use as a real proper scope, but they do the job. A PC based scope is even cheaper but not quite as convenient for some jobs. Have not used mine for a couple of years now so maybe not my best investment. ?.

 

I reckon one of those little USB cameras might be really useful on a boat.

 

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

[WotEver]

1 hour ago, dmr said:

ooh thats a big link ?

Indeed... I have something similar (different box!). 

[GUMPY]

8 minutes ago, dmr said:

You can get a half decent chinese 'scope with a colour LCD screen for not too much money, especially if you are happy not to go above about 20MHz, I know they are not as nice to use as a real proper scope, but they do the job. A PC based scope is even cheaper but not quite as convenient for some jobs. Have not used mine for a couple of years now so maybe not my best investment. ?.

 

I reckon one of those little USB cameras might be really useful on a boat.

 

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

Don't tempt me,.

 

[WotEver]

50 minutes ago, Loddon said:

Don't tempt me,.

?https://www.wish.com/product/5ebf8a9e34418e47b738cfa4

[GUMPY]

15 minutes ago, WotEver said:

?https://www.wish.com/product/5ebf8a9e34418e47b738cfa4

Very nice but I don't need it, want yes need no.

 

[Stevec]

You have various suggestions ref dummey load but you can make your own shunt see the attached PDF. All you need is an ammeter to accurately get a measure of current

to your dummy load and a milivolt meter for the display of amps using the shunt.