• Welcome to the Land Rover UK Forums

    You are currently viewing the site as a guest and some content may not be available to you.

    Registration is quick and easy and will give you full access to the site and allow you to ask questions or make comments and join in on the conversation. If you would like to register then please Register Now

On the bench.

Richie_asg1

Richie_asg1

Posting Guru
Site Donor
This is just a general blog-ish note of whatever comes onto the bench that needs repair with hopefully a happy ending. ;)
Mine are mostly electrical during the winter and mechanical during the summer, but feel free to post whatever you want that you are tinkering with or fixing.
This is mainly about taking stuff apart and seeing if you can repair it before it goes in the bin, but can be fun along the way. :thumbsup: Or making something new from salvaged parts in an ode to Mad Max.

On the bench at the monet is a Power Jack 1200W grid tied inverter that is being awkward.

atmega.jpeginverter power jack1.jpegpower jack2.jpeg
Turned out two of the the output (high voltage) IGBJT's were bad, One shorted, one just a bit near death, but after replacing one the other one gave in.
Bear in mind most inverters hold 340V-400V DC on the capacitors inside for quite a long time after they are turned off, so you have to be a little bit careful of such things during test and repair. Grid tied not so much as the caps are on the low voltage side.
Oh, and usually I don't have the luxury of a full schematic to work from so is mostly feeling in the dark, and the best thing is - I do this for fun!

But this is a Power Jack inverter, So about the lowest entry level gear on the market. So bad in fact they have youtube video of how to repair your own direct from the manufacturers! (in China). If it doesn't kill you or set fire to your home - hey - it might just save you some money. Most units last a few months, don't like being turned off too often, and run hot most of the time. Look at the them the wrong way and they will stop working. This one arrived with a fault light on, but after the first repair and new plug, cable, fuses, still managed to blow both 5A fuses and a 32A main circuit breaker when plugged in.

It is supposed to work up to 55v from a solar panel, but crapped out at 37V from batteries so I think I will buy a panel to test it out then it will be given back to the Ebay community to cause much worry to someone else as it is just a bad design, hurriedly put together and mass produced in China. You can only do so much for such a sick animal, and some won't live long anyway. :sad:
 
I can't see my bench , I need a good sort out, too much accumulated junk filling my garage again and I need to get the hayabusa stripped down soon so the bench will be full again no doubt :D
 
erubus said:
Should have measured the threads and id have made you one.

Are you going to make wooden crankshafts now 🤔
Click to expand...
Many moons ago ,I went with the BBO on his Bonneville to Broadway Motors in Stoke for an Mot ,the two old fellas there must have been there since the war and it was a mine of parts for all makes of British motorcycles. I always got a grubby mug of tea of them ,the men didn't .They used to test the brakes with a strap round the forks to a winch with a spring scale ,if the bike was dragged across the floor with out the wheel turning it passed. Any how there was a Aerial Square 4 in for repair ,fella brought it in the winter and had only started to use it in the last couple of weeks ,all was fine ,then it started to lose power and smoke a bit ," rings gone or valves ? " says the BBO . No says the fella, we whipped the head of and found this ! A beautifully turned piston made from wood (lignum Vitae ,I think) with an hole brunt straight through it.. I was amazed it worked at all. They had seen one before but the most common dodge was to fill a gearbox with grease and sawdust to quite down a knackered box long enough for the poor mug to see it spew its contents out a few miles up the road .Sorry mate ,sold as seen !
 
On the bench, still on breadboard is a little thing I made that extends the daylight for growing seedlings on a windowsill.
It's a common problem that gardeners face where the light at this time of year is not enough for the seeds so they stretch and become long and leggy as they lean towards the light. You can use grow lights with a mains timer, but this way may be simpler.
This one is designed to use a 5v USB supply, and power 5v usb striplight LED's, and it plugs neatly between the two.
Using a light dependent resistor it operates in reverse to normal so it comes on during the day and goes off at night, but it also dims the light to nothing during strong daylight - so it is only filling in the gap at dawn and dusk at full power, and adding a bit on dull days.

I've got it on a 3m length of lights which is a bit much, and monitoring the power transistor temperature at the moment to see if it needs a heatsink. So far it doesn't even running 3M of them.
After making what I need, I may sell them as a kit, or build them up and try that way if there is any interest. Should only be a few quid as the parts are cheap.
Daylight Extender.jpeg
 
I don't want to talk about it. After 5 hours of designing and making some cargo brackets out of aluminum sections to fit our little folding boat I have thrown the whole lot onto the scrap ally pile. There came a point when the flaws in the whole idea could not be denied and it was best to stop. Most of it began on the scrap pile and it ended there too (plus rather a lot of pop rivets and swarf.)
 
Nearly there on the daylight extender. Usually by now I'm getting pretty fed up with the design & R&D and just want it finished and out of the way.
Screenshot (84).png I downsized the output transistor, and added a 5v regulator, so now it is a dual purpose board and can work with 12v or 5v supply for 12v or 5v lights, just by removing the regulator and adding a jumper instead. Tested and tweaked it uses 5.1mA in the dark which is mostly the LDR sensing voltage divider.
Quite freaky on cloudy days as it ramps up and turns on and off as clouds pass. I imagined a whole greenhouse lit with these would look a bit sci-fi.

It may be better to monitor the light from underneath the lights at plant level, and dim the area lighting to maintain a constant lumen level, up to a timed turn off if I was a large scale user.....
But this will work for home propagators and time to push it out there.
 
Still not had time to sit and assemble these, and as it is summer now and everything is growing there is not as much need right now. I did have two LED's blow out on my growlights, but they were a quick fix.
Working my way through Mikeau's amp. 240v to 110v Transfomer turned up today.
Stripped the petrol strimmer today, cleaned carb out but need a new gasket so one now ordered. Why can I only buy it from China? Actually 4 ordered, so I can sell 2 on and help out some other poor sod this side of the pond.

Found an interesting picture to describe my projects and why some of them bog down in the middle, leading to abandonment.
1_x4lvpEOn_4J7tI_wqIeN3w.jpeg
 
Back
Top Bottom