saturated's all encompassing inclusive and exclusive bin thread

[Tassieviking]

I love your dedication to learn electronics, not many people would take it upon themself to do it so thoroughly with textbooks and lessons.
By the end of this year I think you will be good enough to really get into pedal designs and even amplifiers.
It won't be long before you can start designing your own PCB's and have them fabricated so you can build your own projects.
It is great fun when you want a pedal that is no longer made and the old ones are costing a fortune, make them yourself really cheap.
Keep up the great work.
Cheers
Mick

[saturated]

I thought I would I submit a graphical image of how I feel when you and the others are discussing tech in other threads





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But thanks you guys rock   

[saturated]

Last night I learned that he/she who uses multimeter to measure current but forgets to switch positive lead back before measuring voltage finds themselves looking online for a $30 fuse

    

[Tassieviking]

That is too much for a normal fuse, what type is it ?
Photo ?
It is usually a M205 fuse that costs cents, sometimes a ceramic type but still cheap.

[g1]

It is usually a M205 fuse that costs cents, sometimes a ceramic type but still cheap.

My meter uses a regular fuse for the 2A range but has a special fuse for the 10A range (that has it's own probe port).
The special fuse is very expensive due to safety ratings and odd size.
You can find cheap ones from China but I think they are fake as far as the safety ratings go.
Mine is not a Fluke, but this will give you an idea:
https://www.fluke-direct.ca/online/fluke-instruments-replacement-fuses

[saturated]

Thanks guys
Trying to remember from last night but I think it is called amprobe fp700

2A 1500V fast blow

8x65 mm

[g1]

$30 is for a 2-pack, looks like you can't buy them separately.

[Tassieviking]

Crap !!!!
I just went and pulled apart 2 of my Flukes and I have weird fuses as well, I think I have replaced some a long time ago as well but the company I worked for had a draw full of them.
I wish I had kept some spares with the meters now.

No wonder I have some cheap Uni-T meters on the workshop bench, I think they cost around $30 when I bought them. (Many years ago). I know they use cheap fuses as I blew one working on my car.

You can get some fairly decent meters on Ebay for under $20 ($10 up) that are ok if you are only working on low voltage stuff at home for yourself. I would only get Cat3 rated stuff at least.

I will leave my Flukes to have a rest unless I decide to start working for a living again.
I do not need a good meter anymore as the highest voltage I work with now will be  240v mains in my own gear.
EDIT: maybe a bit more in valve amps (a lot more).
Any Cat3 meters should be enough for any private use I think.

[saturated]

Roger that

These days can buy entire meters for that. 

Anyhow I ordered a pair

Lesson learned $$$

I will def have a dedicated current lead/probe with an unpleasant note and warning on the minigrabber portion.

 

 

[Tassieviking]

I have seen multimeters that physically block the holes when you turn the knob so it is only possible to use the volt probe when volt is selected and only amp plug when amps is selected, but it was many years ago.
I wonder if you can still get some like that anymore, maybe it was just a temporary fad that went for a while.

[g1]

I have seen multimeters that physically block the holes when you turn the knob so it is only possible to use the volt probe when volt is selected

I think if you forget you were in current mode, you will likely to forget to turn the knob as well.  So then you would still do damage with the probes, which are acting as a straight piece of wire in current ranges.
My current range require switching ports, and there is a beeper that goes off if I choose any other range while plugged into the 10A port.
Still doesn't help me if I forget to switch range.   

[saturated]

Ok guys back in business

Got my fuses in this evening

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Despite shaking in my boots I proceeded

Read the manual and they said remove front six 2mm hex head. So I did that then spent like 30 mins trying to separate the case halves had to use an ice scraper and I didn't think it would ever happen.  But finally slowly but surely they opened up to a great sigh of relief. 

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Removed the old fuse and tested with another meter...open.

Put everything back together and now reading current once again

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Some good news I was wondering if I had to do this all over again to change the battery but it has a separate door.

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A startling fact when I went to test I found my power supply had been on since the mishap
I went to plug it in and it was already plugged in. Then I went to turn it on and....it was already on.    
 
Gonna have to put up a sign.

But at least the voltage control was turned all the way down. 

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So hey all good I suppose that was fun but had to spend some money

 

[saturated]

Wow that power supply was on for eight days
 

Oh well one time I was reading about tv station or recording studio or some type of place like that and they never ever turned anything off and that was when they had tube equipment.  And some noob trying to do a good job would get chewed out for turning something off.

 

[g1]

Lots of modern electronic equipment has standby circuitry that is always running unless you unplug it from the wall.

[saturated]

So I got to thinking why don't I just put a fuse in my test lead that is less than 2 amps.

It should be plenty for my little Micky 🐭 Mouse 🐁 experiments.  It's not like I'm in a plant or industrial commercial setting poking around.

So I looked around my collection of glass and blade fuses to see what I could come up with.  I was sure that I could scare up a few fuse holders that never got used and accumulated but couldn't find any.

So now that is the plan.  I would have liked to find a 1.5 A fuse but I only found stuff like 0.5 A and much larger.
And all in glass none of the blade automotive fuses were less than 5A maybe 10.

So I had always wondered about voltage ratings on capacitors and fuses and I'm guessing that a component with a lower voltage ratings will be shorted like arcing by a higher voltage.

For example if I have a 250v fuse and I apply 1500v it will short/arc/jump across it?  Rather than open as intended.....idk just thinking out loud maybe I'm wrong.

I know when I had a HV probe and tried to check some HV on an oscilloscope it didn't help it arcd and sparks flew like crazy.