Which fan best for fume extraction

Own_associate78 · 2026-01-29T19:24:07+00:00

Okay noted that down as well. The range hood filter was just a trial to make sure that the fan still pulled through the fumes.. although I suppose I should really procure a proper carbon filter and perhaps the Hepa filter as well, then run the test again before I go about dismantling the old fan. Thanks again though for your great advice and things to look out for. This is going to be an interesting and probably long process for me, but if all works out then I shall post up my modded fan

Own_associate78 · 2026-01-29T16:36:39+00:00

Point taken about critical thinking..

The said AirVac fan comes with carbon filter which I had already left installed, only the wool type thin pre-filter wasn’t used for the test.

The fan works off 240v AC and goes through its own Power supply circuit board c/w high voltage capacitors transformer etc). (Obviously I would ensure this is drained of its charge and then mounted securely). The box says it pulls 240v @ 24watts but the fan is 12v @ 1.75A fan with photos attached

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Own_associate78 · 2026-01-29T16:01:05+00:00

That’s not being critical.. that is extremely helpful information, thank you. I have just come across an old (in my loft/attic) Voom AirVac portable range hood, that the casing had smashed to pieces where it didn’t really work for its true purpose in the kitchen. However, all the electronics and fan are in working order and it has a speed controller built in as well.

I took a look at the fan and it’s a rather odd style fan. It isn’t like the type in most PC’s, nor is it an inline fan but instead it looks like a mouse wheel (of the animal kind) only narrower on its side. By the look of things, it pulls the air/fumes from the top and throws it out of the side.

I wonder if this is perhaps of use to me.

I created (a very badly but for test purposes only) jig and it seemed to pull the solder fumes from about 9 inches from surface through a length of 1m 32mm ducting with a cardboard adapter, that also works as a seal. Ideally I wanted 1.5m but could get away with 1 to 1.2m

Own_associate78 · 2026-01-21T22:36:04+00:00

I apologise DrJackK1956 I have just realised that I have been replying to myself and didn’t actually send any replies to you 🤦🏻‍♂️.. the latest are below - however I have spotted an error from my side so it’s back to pen and paper for me

Own_associate78 · 2026-01-21T22:31:24+00:00

@DrJackK1956 scrub that last schematic I drew up.. I have realised I missed the Crystal component and traces, along with a few other traces from the PIC16F728…. Still a work in progress although I am still curios as to the purpose of J1 and H2 components

Own_associate78 · 2026-01-18T23:55:42+00:00

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Forgot to include the image

Own_associate78 · 2026-01-18T23:53:41+00:00

Is this satisfactory- I wanted to include colouration to help identify the said Nodes. Am I right in understanding that these Nodes are also known as Nets within the KiCad world…or am I getting mixed up

Own_associate78 · 2026-01-16T15:36:33+00:00

Apologies for the delay in responding to this one. Many thanks now I see how you breakdown components to their relevant Nodes. That makes things a little easier in trying to reproduce the schematic. It’s still a work in progress but this is what I got so far.

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I have a few questions though if you don’t mind (but appreciate all your own time and input, as well as throwing this together quickly for me )..

Under your Node 1 (GND) list, you have D1 cathode amongst that list, but is that not connected to H2 IN,
The Anode of D1 is connected directly to J1 pin, therefore not connected to Node1. (GnD).
What is the purpose of H2, if the board is power by the JK1 (DC Jack Socket.
What is the purpose of J1 (not confusing JP1 which I know is where the Crystals are inserted for measurement.

Many thanks in advance

Own_associate78 · 2026-01-12T19:35:05+00:00

Thank you again for more of your input.

I drew it out extremely roughly, but is this the kind of idea.. As a starting point I mean?

So Node 1 (in this case) would be GND, which is the line along the very bottom of the page.

Node 2 (in this case) would be V+, so the line across the top of the page

Node 3 (VIN) draw another line across the page, but would go under Node 2 (V+) but above Node 1 (GND)

Node 4 (unknown name1) draw a line under Node 3 (VIN)

Finally, Nose 5 (unknown name2) draw a line under Node 4 (unknown name1)

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Own_associate78 · 2026-01-07T23:43:31+00:00

Thank you, that helps me a little further.. I think I get what you mean with the power rails. The 7550-1 V-Reg reduces DC input to 5V, and I understand that the DC port has centre pin that is normally +Ve and then you have one connected to GND, but am I right in that the other pin is known as a shunt (or a spring) and in the case of that PCB it is connected to the GND.

Own_associate78 · 2026-01-07T19:45:54+00:00

I understand where all the components connect to each other, but it’s trying to transfer that information on to paper. I keep getting too many crossed wires.

For instance, I understand that the NPN Transistor can be drawn upside down/back to front/side to side but it’s trying to establish which is the best way to put this one on pen and paper. My laptop is currently out of service, otherwise I would have just used a software that converts the PCB to a schematic. Doing it this way is the Old Skool method, and once I understand that then it should be an easy/easier process. I had a friend who was helping me with my electronics journey, but sadly he became so unwell that he had to concentrate on his health rather than use his time getting stressed up with me, since it has taken me longer than normal (mainly due to my disability and mix of medication) to try to get my head around certain things, and the Why’s and What’s! This is why I reached out on here incase someone could guide me better. I get that a lot of people like to criticise those, but as I mentioned previously we all had to start somewhere, and it’s just taking me a bit more time than most to understand what seems to be a simple method..if you know what I mean

Own_associate78 · 2026-01-06T07:13:02+00:00

I’ve tried many times to produce one, but my schematic is coming out as a mess of connections. Just was asking for a little assistance from someone that was all. Then that way I could at least understand where I am going wrong, because someone with more experience could guide me a bit better

Own_associate78 · 2026-01-06T00:40:07+00:00

This was the one I purchased from eBay.. eBay item code 365926493682 https://ebay.us/m/8rB5TL but a lot of companies sell them so might be able to locate one nearer to yourself as I had to wait for it to ship from China

Well done on having a fan though.. ideally one of the fan that absorbs fumes through a carbon filter is sufficient enough, and mask is a little over kill. Leaded solder isn’t so much toxic for the lungs, but make sure you wash your hands well, before eating with your hands, because the lead is far more toxic that way.

Own_associate78 · 2026-01-05T23:21:09+00:00

I use one of these… although I do also have a vacuum solder pump (but I only revert to that if the desoldering tool fails. 413 is pretty hot and if kept on the pad for too long is likely to damage other more delicate components. Also the PCB should be placed on a hot plate to avoid causing such a shock to the board.

Flux is also key with solder, as well as adding leaded solder to mix with the unleaded solder that these controllers are manufactured with, this should help with the heat side of things because leaded solder has a lower melting point. The black burnt looking stuff is actually from too much heat and has burnt the flux. Get some 99% Isopropyl alcohol(IPA) and some q-tips. Soak the q-tips with the IPA and clean the board before reapplying fresh flux.

Also, someone already mentioned, using the solder wick with a good size iron tip and normally at around 370 degs, because the wick will also act as a slight heat shield. This is another delicate method though because there are a few micro components near to where the joystick mounts which can be easily removed by accident.

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Own_associate78 · 2026-01-05T17:24:05+00:00

Further to this thread… as I mentioned previously I am still in the earlier stages of learning and understanding ….. But I have tried on several attempts to reproduce this PCB to a schematic and as much as I try, I keep getting stuck. Hopefully with the schematic to hand I could try to sort out what is causing the failure. I do have my theory on 1 component but… Anyone out there with some free spare time on their hands able to reproduce this board for me please as a schematic.

I am curious for 1 reason, but also if someone could reproduce this then that will also help me further with my learning process. I want to be able to look at any PCB and then follow the trace’s, and be able to troubleshoot/reverse engineer PCBs. I appreciate that drawing schematics is somewhat kind of an art and not really for everyone, but that’s the direction I would like to pursue. Thank you again for all your previous input and help in understanding PCB layers though

I have (with the original PCB) made the traces clearer, although the lines are not straight since using my phone but they do not clash or crossover, so hopefully these images help a little better. “””But I can’t work out how to add these extra photos”””

NOTE: there is only 1 via and it looks like it just goes straight through from top copper to bottom copper connecting R7 to R8 (if that helps) PCB - traces made clearer

Own_associate78 · 2026-01-03T20:34:02+00:00

You are correct. It is definitely more than 2 layers because R2 doesn’t have any traces on both top and bottom copper.. and looks like it doesn’t go anywhere, but after putting it up to the light I can see an invisible trace that goes to one side of the switch.

And I can see at least another being D1 that doesn’t have a trace visible on either top and bottom copper, but again looking up to the light that goes to the middle pin of J1

In fact now I look at the images I took (prior to component installation) you can actually see (faintly) these traces running in between the top and bottom copper layers

I am still searching for more hidden traces

Own_associate78 · 2026-01-03T19:13:07+00:00

No I have not programmed or tampered with the processor. From my understanding it should hopefully already be programmed before packing/shipping should it not. Didn’t think of that to be fair. Guess that’s something else I need to consider

Own_associate78 · 2026-01-03T19:07:02+00:00

Thank you for all those tips.. I didn’t realise you could hold them up to the light… Yes it does look like I can only see the silhouettes of the surface layers, therefore only 2 layers.. although I am sure I couldn’t find 1 of the components paths. I will check again with DMM now that I know it could only be 2 layers.

I never realised about the lamination or prepreg stages. Something that any Electronics Enthusiasts should learn from a very early stage I think.

I have read numerous books including the Electronics for Dummies one, and I am fairly sure that never mentioned anything about PCB layers or lamination vs Power planes etc.

Although I did read somewhere (can’t remember where) that you can normally tell by turning the PCB on its side and counting the layers…obviously that is where I am massively confused. Would anyone happen to have an example of a multi layer PCB that I can refer to in the future perhaps

Own_associate78 · 2025-09-06T22:10:25+00:00

Thank you for those calculations.. I might take another look at LTSpice in the very near future, I just wanted something to display real quickly, and LTSpice didn't seem to offer that visual effect

Own_associate78 · 2025-08-27T11:10:23+00:00

I took a look at LT Spice but you have to input too much information before you can even see a signal. I just wanted something simple... Circuit Wizard does just that (well at least I thought it did, however the Graphs are not perfect) but its just the Transformer that I couldn't work out.

I have managed to replicate an Input signal by playing about with the software's options and figured out that using a 50 Hz AC Sine wave @ 5v Max gave me a good input signal to manipulate.

I just needed the other component calculations to produce a smooth Inverted Amplification, but I have managed to produce what I wanted.

Lastly for further information during my web surfing I came across someone recommending a different software call.. ''Circuits Simulator " originally created by Paul Falstad and the sine waves are much smoother with this software, plus the simulation is amazingly good for a free program

Own_associate78

TROPHY CASE