Basic problem with transistors

[Nigel Goodwin]

Indeed I did mentally groan at the mention of soldering every contact on, but hey it's good practice and I certainly need it

Have you seen the price of the crimping tools?

 

[giftiger_wunsch]

Rapid had a crimping tool for £17.50, that doesn't sound so bad. Not worth it considering this is likely to be the only use I'll ever have for it though.

 

[Hero999]

Are you sure it will work with those crimps?

 

[giftiger_wunsch]

Are you sure it will work with those crimps?

...no. though I found it because it was a 'you may also be interested in' from the page you provided, so it probably does. But either way, a bit of soldering experience won't go amiss.

 

[audioguru]

The cold solder joints made by the NOOBs here allow the wires to be pulled out of the solder joint (rosin joint).

Most crimped joints I have seen also allow the wires to be pulled out of the joint.

Nobody can pull apart my properly soldered joints. my Weller soldering iron is always at the correct temperature for good soldering (tin-lead solder).

 

[giftiger_wunsch]

Ouch, the way you say NOOBS like that cuts deep AG

I'm getting better at desoldering joints as I've been practising removing components from a VCR circuit board (I was quite chuffed when I managed to desolder all 21 pins of a scart connector ) but I'll need to get some more actual soldering practice before I even consider poking my microprocessor's prototyping board to attach the headers

 

[audioguru]

NOOBs connect parts backwards and fry other parts.
Since their soldering irons get way too hot then their solder joints are hopeless.

Most NOOBs destroy the fuse in their digital multimeter in the first couple of days.

 

[giftiger_wunsch]

I feel better now, you just excluded me from the NOOBS category

 

[audioguru]

I feel better now, you just excluded me from the NOOBS category

Why, didn't you destroy the fuse in your digital meter yet?

 

[giftiger_wunsch]

It would worth a major forehead-slap if I ever soldered a component in the wrong way round, and the only time I've ever placed a component the wrong way round with a breadboard is when the manufacturers clearly hadn't heard of the convention whereby the slightly longer lead of an LED is the anode

I believe the fuse on my digital multimeter is 2A and is part of the circuit labelled as 200mA so that would also be a pretty epic fail.

I won't say my solder joints are much short of hopeless but at least I can recognise when they're hopeless and try again rather than leaving them to destroy whatever I was building.

 

[Hero999]

I've blown a few fuses on DVMs, it's so easy to leave it on the current setting, then try to measure voltage.

Be carful with tantalum capacitors, the band is the positive which is totally opposite convention to aluminium capacitors, diodes and everything else.

 

[giftiger_wunsch]

Be carful with tantalum capacitors, the band is the positive which is totally opposite convention to aluminium capacitors, diodes and everything else.

Clearly they felt like being awkward when they came up with that idea

 

[audioguru]

I have never blown the fuse in a multimeter, blown a transistor nor blown an LED.
I do things correctly the first time.

 

[giftiger_wunsch]

You're basically saying you never make mistakes? Ever heard of 'god complex'?

I've never blown a fuse, transistor, or LED either. There's a first time for everything though.

 

[Hero999]

I have never blown the fuse in a multimeter, blown a transistor nor blown an LED.
I do things correctly the first time.

Come on, I don't believe that audioguru.

 

[audioguru]

Come on, I don't believe that audioguru.

My first projects were kits:
A vacuum tube stereo amplifier.
A vacuum tube FM tuner.
A vacuum tube stereo multiplex adapter for the tuner.
A vacuum tube oscilloscope.
They used vacuum tubes instead of the mechanical valves that were used in the UK. Hee, hee.
A transistorized multimeter.

Then I made projects from magazines:
A transistorized Wein bridge oscillator.
A transistorized FM transmitter.
A pro-logic quadraphonic adapter with ICs.
A VU meter with two LM3915 modules (complete with LED arrays).

They all worked perfectly and nothing blew up.

 

[Hero999]

I notice that none of the above are high voltage projects, switching regulators, which are liable to failure, and were not designed by you.

All the projects I've made have worked in the end. The only time I blow components is when I'm breadboarding or building prototypes. When I was a kid, I used to do stupid things such as use the wrong value of series resistor for LEDs pretty often, now I'm grown up I don't blow things up much.

There two occasions when I've blown components after growing up:

1. I soldered an SMT tantalum capacitor in the wrong way round and it exploded, yes I learnt the hard way.
2. I tested a TV flyback driver on an antistatic work bench, it arced onto the bench and back to the MOSFET, causing it to smoke. It made a nasty burn mark on the bench which I covered with an antistatic mat.

Both of the above happened when I was at work.

Nowadays I don't bother building a prototype for most of my projects and they work first time. I only bother prototyping things that need tweaking, most things don't.

 

[Nigel Goodwin]

I notice that none of the above are high voltage projects, switching regulators, which are liable to failure, and were not designed by you.

Most of them were high voltage, as they used valves (the correct name from the inventor!)

Switching regulators didn't arrive till decades later - first ever domestic use the Thorn 3000 CTV, about 1972?.

 

[giftiger_wunsch]

I'm just getting into electronics but I have made the incorrect resistor values for LEDs mistake; though in my defence that was largely because I was given misinformation about their working current. Fortunately I somehow failed to damage any of the LEDs I overloaded. Now I know to check the datasheet rather than guess

 

[giftiger_wunsch]

Anyway to wander back to the matter, any idea how I might find out if the molex housings will fit over the (non-molex) headers I linked to before? They have the correct pitch, but the molex data sheet on rapid doesn't indicate the pin dimensions so I don't know if they have the correct cross-section dimensions. If molex headers have standard pin dimensions, perhaps I can find out what these are elsewhere?

Edit: Checked data sheet for a fourth time and found they were mentioned, just not annotated on the diagram. They are 0.64mm square, just like the other headers. So it appears the molex housings will fit perfectly on the cheaper headers. Time to finally order all these components, it seems.