General activity – Page 2 – Woody's Workshop

September 29, 2022September 29, 2022

Technoline Wireless Weather Station problem

WS-2350 Poor Battery Life

I have had my WS-2350 Weather Station for a very long time and it has always worked reliably. The batteries recently died in the base station unit (3 x AA) and I replaced them. The unit sits in the kitchen and on entering the kitchen the following evening I noticed a glow coming from the LCD screen backlight LEDs. This was unusual as the LEDs should switch off after a few seconds of a key press. I didn’t think anymore about it and went to bed. Next morning the low battery symbol was showing…. and the LEDs were still dimly showing light.

I took the unit through to the workshop and powered it from a 6V external supply. Sure enough the LEDs were on and the current drawn was around 40mA, far too high for long life battery operation.

I removed the eight screws holding the case rear in place and struggled to remove it. There was a build up of corrosion around the battery contacts making them tight in the back cover moulding slots. Some careful cleaning eventually cleared this and the back cover came off. This revealed more accumulated ‘fur’ corrosion around the PCB lands holding the battery contacts and elsewhere on the board. This was cleaned off but the current drawn still remained high.

I next removed the PCB from inside the case. This needs six screws to be removed. A word of warning. These six screws while holding the board in place are also responsible for applying pressure to the conductive rubber contact strips that connect the LCD screen to the PCB. Be very careful not to disturb these strips. The board is also connected to the VLF rod antenna that receives the off air time code updates and also to the antenna for the radio transceiver that connects to the outdoor sensor module. Be very careful not to disturb these components.

I gently lifted the PCB out and sure enough there was even more corrosive fur on the back side of the PCB around the battery terminals and elsewhere on the board. I thoroughly cleaned all this off and with an abrasive pencil brightened up the the battery contacts.

After fastening the PCB back into the case, I powered it back up from the external supply. To my relief the LCD had re-connected okay and was fully working. More important was the power consumption had dropped to microamps. Problem solved. The corrosion somewhere on the board must have been creating a partial short across the PCB tracks. This must have been sufficient to make the processor think a key was still pressed and therefore the backlight LEDs needed to be held on.

As I had never had leaking batteries in the unit I would guess that there had been soldering flux left on the board when it was assembled and this had absorbed moisture and had ‘grown’ and become conductive over time.

I hope this helps someone who might be having similar problems. When battery powered devices are running with very low current it does not need much contamination between copper tracks to cause all sorts of weird effects.

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August 15, 2022August 15, 2022

Rainwater Harvesting installation

Experiences with garden irrigation water pumps

First of all some background and then the techie bit at the end.

Some years ago while we had extension building work undertaken on our house we opted to install a large underground plastic water storage tank (>3000 litres). This was supplied complete with tank and submersible pump from Rain Water Harvesting. The tank is topped up with water from all the house roof down pipes. The water stored is used for all external water demands such as garden watering and car washing etc. We get a discount on our local authority water rates for having such an installation.

The house is fairly old and some months after the extension work was completed we began work clearing the garden. In the process of this clearance we discovered a cast iron manhole cover buried deep in the vegetation. On lifting the manhole cover we discovered … another underground water storage tank. This was of brick construction with a cement skimmed surface and doing some quick calculations appeared to be a similar volume to our recently installed new tank. The tank appears to have perhaps fed a hand pump or similar but it is unclear where the incoming feed originated. We added some new guttering to an adjacent building and the run off from this roof now tops up the old tank. Here is a view to the murky depths with the new pump and incoming feed installed.

The original pump suppled by RWH eventually began to give problems and started to blow the electrical breaker. RWH were very helpful and a new pump was supplied and installed. After some period of time it also began to become erratic in starting up when it saw demand. A third pump was then bought and installed. I also bought a maintenance kit for the second pump and then installed it in the old brick tank. The maintenance kit was very good and includes a new Hall Effect switch to sense flow demand. RWH support fitting the maintenance kit with some very good instructional videos. The second pump worked for a good period in the old tank but then started to blow the associated electrical breaker.

Rather than buy yet another RWH pump I opted for a more expensive solution from Pump Technology who are a local company servicing industrial pump applications. The new pump (Divertron 1200X) was more expensive but does appear to be of a much more professional build quality. It stands vertically in the tank and has a floating inlet pipe which ensures the water is drawn into the pump at surface water level rather than from the murky depths where all the accumulated silt sits. So far both new pumps are behaving well and have been a boon to keep the veg plot irrigated in the current very hot period.

The important issue that comes to light is the logic of the pump demand sensing logic.

The pumps sit quiescently at the bottom of the tank and look for a flow in the output pipe in order to turn on to meet the demand. They also have protection circuitry that detects against what they interpret as leaks which would lead to the pump hunting and potentially overheating. After a number of hunting starts the pumps go into reset mode and need a power reset. Similarly if the tank runs dry they also switch off. The problem with the logic occurs where you have a dribble irrigation system or a leaking tap union. The dribble irrigation nozzles do not give a full flow so the pump hunts for a number of times to satisfy demand then interpret this intermittent demand as a leak and switches off. Likewise if you have a leaking tap union the pump sees this and eventually switches off. If you are trying to protect your veg plot using timed irrigation both these problems cause the pump to switch off and only work again after a power reset. This doesn’t help when you are out of the country and believe your garden produce is being watered.

Clearly weeping tap unions can be fixed so that clears that problem but a dribble system is more of a problem. My solution is to mask the presence to the pump of the dribble system by having it timed to run in parallel with the main sprinkler system. This seems to fix the problem and no more ‘hard bounces’ are then needed to the pump electrics.

The other method of solving both intermittent demand sources is to fit a pressure vessel in the pump output feed. This acts like a water based ‘capacitor’. The bladder in the pressure vessel fills with water at full pressure and then supports the dribble demands from leaky taps or dribble irrigation systems to mask the effects to the pump sensing logic. I have bought a pressure vessel but not installed it as yet.

My thanks to Rain Water Harvesting for all their support over the years and it will be interesting to see how the new style pump behaves long term. I believe RWH also offer the Divertron 1200 X pump.

Sorry if that was a bit boring but it might help someone somewhere who is having the same issues with erratic pump operation and resulting withered vegetables.

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June 22, 2022

Fathers Day gift makes me smile

It was Fathers Day last Sunday and apart from spending time watching the very exciting final round of the US Open I had a visit from one of my sons and my granddaughter.

They came bearing gifts … a pair of socks. Not just a pair of socks but a very appropriate pair of socks.

Bamboo brand socks with 'I'm an engineer - What's your Superpower' motif

It is a Superpower that we as engineers hold through our hands and our brains.

If we could just get the younger generations to understand the importance of engineering and how it creates wealth for our country and in turn contributes towards our future survival as a race.

A great Fathers Day gift. Thank you.

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November 17, 2021November 17, 2021

Engineering Video Favourites Updated List

As the months (and years !) have passed while authoring this site, my favourite YouTube sites have morphed and changed as my skill level and interests have become more focussed. The other aspect is that many of my early favourites have just faded away and now rarely post if at all. I guess it takes a great deal of commitment to create regular footage over a long period of time so it is understandable that people come and go.

At the risk of everyone clicking and leaving, here is a share of the sites I now look forward to visiting and viewing : –

Top of the list is Clough42 for his highly professional, regular posts on home workshop activity but key for me is his use of Fusion 360 for all his engineering modelling.

I met Jimmy Diresta at NYC CNC in 2016 and I love to watch his almost ‘off the cuff’ creations in metal and wood.

For TIG welding I have watched many sources but Pacific Arc TIG Welding is my current favourite and Dusty does some amazing stainless TIG welding artworks.

I need to mention This Old Tony even though he has been absent from the scene for a long period. He is now back and on top form.

Then of course for serious CNC activity there is John Saunders and John Grimsmo. Both these guys have done incredibly well as they have emerged from their garages and blossomed into YouTube stars.

Finally a less well know site for Fusion 360 is Mechanical Advantage hosted by Kevin who was my instructor on the NYC CNC Fusion 360 course. Really nice guy and always helpful if you have a problem.

So that is my current short list of ‘ones to watch’. If you haven’t discovered any of them then check them out. But don’t forget to come back here every now and then just in case I get up to something interesting.

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August 23, 2020August 23, 2020

Windows 10 Upgrade and another day dribbled away through my fingers

We are sitting in quarantine and now on Day 5. Not really any different to how we were before we went to France and when we were in France – just different jobs around the house and workshop and zero outside contact other than food deliveries. (My wife gets very excited at the prospect of seeing the deliveries arrive).

I got fed up with the boot warnings on Fusion 360 that Win7 would not be supported so I decided that I would upgrade to Win10. My machine is fairly well spec’d so there was no great desire to upgrade to a new machine. It was i7 based and had 32MB of memory with a 250GB SSD and a 1TB secondary drive. Both drives were pretty full and into red warnings so I bit the bullet and opted for a clean load. I bought in a new 500GB for the operating system and app storage and a massive 2TB data storage secondary drive. Total cost under GBP100 which is staggeringly cheap.

Changing the hardware was simple. I bought in a SATA to USB dongle to allow the old drives to be available for data transfer and this made life a bit easier.

Loading Win10 and all my favourite apps took over a day. It is just never simple. Finding software keys is always a bit of a problem as some apps hide it away in Registry. Finding EXE loading files is another frustration. Why when you buy an app do some providers send you an email link to download direct with a licence key ? This results in nothing showing in ‘Downloads’ history to refer back to and reload the app. When you try to use the old email link it downloads the latest version and tells you that your licence key is no longer valid. When you go to their site the version that did everything you ever wanted has been upgraded and needs you to pay to now use the later version. ‘Hello .. I have paid for version X and I don’t want to pay for version Y thank you very much. Just give me a download link to restore what I know and love”. Rant over on that one.

Some weird effects on Outlook transpired. I have a GMail IMAP account and three POP accounts all loaded on Outlook. After loading I had an extra ‘Sent’ folder on the GMail folders tree which contained the Sent items from one of the POP accounts. Spent a lot of time on this and didn’t satisfactorily solve it other than deleting the contents from this duplicate folder. The messages are still there in the POP folder so not sure what that was all about.

My 3DConnexion Spacemouse loaded across fine onto Win10 but I still had a related exception error window coming up on booting the machine. This was the same as it had been on Win 7 so clearly something was common mode. I could click it and the message window would disappear but it was annoying. After some digging I traced it to Trend Antivirus. If I put the two 3dconnexions’ Windows folders into Trend as ‘Ignore’ items it all went away. Progress on that one.

So I think I now have a (mostly) stable Win 10 machine. I hate all the nanny state Windows ‘fluff’ that stops you getting quickly to things such as System\Hardware like it was in XP. In an attempt to ease this I have loaded Stardock’s ‘Start 10’ which mimics the old style Start menu and this makes me feel a bit more familiar.

Hopefully this was all worth doing and things will now go swimmingly along with no crashes and dramatic improvements in productivity …. gosh were those really pigs I saw flying past ?

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