In The WEEE-k #1 - my little segment!

So I decided to make my own little segment about what i found int he WEEE bin at work. Basically DUMPSTER DIVING.

So in this video I basically explain what WEEE is and what I found out of my first haul!

Hopefully for my next video I'll have them displays fired up and then move onto my next haul!

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Not brighter but longer!

I recently bought a second hand Makita drill and torch that came with 3 12V 1.3Ah batteries. The batteries are a but suspect: they go flat really quickly and take a short amount of time to charge from flat.

Anyway to extend the amount of time I can use the torch, I decided to modify and upgrade with an LED out of an old head torch that had its casing damaged.

Here is the torch before with a full charge and about nearly an hour and a half later:

 The upper picture is at full charge, nice overall coverage of the light, that you can work by. The lower one, yeh, not so bright now, and if you doing a job that takes a while, its not something you want.

So I took the lens cover off and found the bulb was a 12V 0.7A filament bulb (plus a spare), meaning it would drain the battery after 2 hours.

Behind the lens cover

So I wanted to use less current but get roughly the same brightness or a suitable amount of light I can work by. So an LED seem and obvious choice, but how to drive it? Current limiting resistor? Constant current circuit!

The LM317 is a wonderful IC, and makes the perfect current limiting circuit with low component count and cost:

In this case the LOAD is an LED. Now I had no idea what the maximum forward current on this LED was. But it was a beefy looking thing on its own PCB. So to be on the safe side I built the circuit on a bread board and connected up to a 12V battery. The value I chose for R1 was 22R, which gave be a current as near to 50mA as possible with the resistors I had (1.25 / 22 = 56mA). The reason for 50mA: well its a beefy thing and some 5mm bulb LED can take up to 30mA before they start going funny, it was an arbitrary value above that.

Here's the LED connected up with the lens over it:

The reflective surface in the lens assembly does make it really bright! Settling on 22R for R1. I build my circuit by just soldering them up and covering any bare contacts that could cause a short with heat-shrink:

Some gratuitous use of electrical tape around the bare metal on the back of the lens assembly to stop the LED to shorting to it and then held the LED in place with more insulation tape. I then stuck the LM317 to the back of the LED and held that with yet more insulation tape. Not the most neat or secure way but for now its just a proof of operation, working prototype. If it does fall off then no biggy, I either apply more tape or use an adhesive, or come up with a more secure method.

I removed the white plastic holder from the torch and removed the conductors and prep'd them for soldering by clipping them down. To do this I had to remove the head of the torch by moving it beyond the straight up position and sliding it off the body. Once the contacts were cut and soldered the driver circuit to them (making sure I was soldering to the correct terminals) I fitted the head back on the torch:

Some strategic placement of hot glue kept the contacts from flapping about. Now came the time to test:

Not bad overall, in a tight spot like under a car it will be enough to work by. But that's not the part I'm pleased about, the battery can now run this torch theoretically for nearly 23 hours off a full charge! I know its probably not precisely the case, but compared to what it did before, that's a vast improvement!

So what could I do with it next: well I did contemplate having a switch on it to switch in another resistor in parallel with R1 to enable a high brightness mode. Another 22R in parallel would make the current about 110mA, which I think the LED can manage but would have to do some testing.

Mini repair update and a quick look at how a starter motor works

So before I chucked the starter motor on my Mini I decided to have a play!

Some history: before starter motors, folk with massive forearms and no concern for putting their back out or breaking a wrist off, used to hand crank engines to start them!

This is how it started, women posing with cars! A bit conservative in them days compared today!

The more pistons and compression the motor had and the finer the clearances between piston and cylinder became, the harder it became to turn them over. Then some genius thought to put an electric motor on the crank shaft and hook it up to a battery - kudos to that guy! bet he made a mint!

Anyway he's me tinkering:

The principle of the starter motor is to engage the crank shaft and provide turning force to compress the fuel and air in the cylinders to being internal combustion. Once the engine fires up, the starter is no longer needed to be connected to the crank shaft.

To disengage the starter from the crankshaft, a method of connecting and disconnecting the motor must be used. In steps the sidekick to the motor: the solenoid.

In this video you can see that the motor has a cog on it that moves to engage the teeth on the flywheel, that in turn is connected to the crankshaft of the engine.

The solenoid moves the cog along the the shaft of the starter motor to engage those teeth and turn the drive shaft. Not only does it serve as a mechanical aid, the solenoid also acts as a contactor for the start motor itself Given that the amount of power it needs to turn the engine over is huge, a bog standard relay won't cut it, it needs beefy thick contacts to handle the current.

This is what happens when you turn the ignition key into the spring back position: your completing the circuit for the solenoid which in turn moves the gear for the starter motor into position on the fly wheel, and then the solenoid completes the circuit for the motor.

I could go into things like cold cranking amps (CCA) and so on for current into the motor from the battery, but that would make this blog longer than it should so I'll just leave a link for Wikipedia on battery terms

Anyway, I want to thank Top Gear Transmissions for a good job and excellent service. Cheers muchly!

Stay Safe!

Hameg M203-6 Repair: Jobsa Good'un - VB#5

So I finally fixed it! MINT!

So the opto had gone bad! its very strange how one day its ok and the next its just not working and all because that opto thought: "nah, not today chief, I'm retired!"

I do burble on a bit about high voltage supplies and my experience with them in this vid so, feel free to spool through, but I'm not implying that you should let your guard down when probing high voltage.

Any way I haven't really got anything else to video coming up, so this may be it for a while.

I think in October I might see if I can go mud plugging, pay and play, so I may post a video just showing some off-road footage. See who's open and fancies a play.

In the mean time, I will post up what I did to convert that torch to LED from filament, it isn't neat, it isn't cutting edge, but it will make your charge go further, which is a blessing when your stuck under a vehicle on dark winter nights.

Stay safe, observe care, and keep your peepers on m'blog!

Cheers!

Bad Support: Scientific ignorance, Bullying and something Batteriser should open their eyes to!

So Dave Jones on the +EEVblog  released another video blog about batteriser. This time on about how somebody, assumed to be affiliated with +Batteriser Batteroo , got a company in Vietnam to dislike his videos debunking the batteriser product.

He also mentions that other bloggers who posted the same conclusions were also under the same attack. This can be shown in their video analytics.

That is pathetic behaviour. what kind of person PAYS to discredit somebody? Seriously are you that desperate for a product that you’d pay somebody else to dislike them? It boggles the mind what frame of mind said person is in!

Now pathetic behavior like this can be laughed off, but when said person (and I say person cos this has gone beyond the action of a troll, and probably somebody who's deluded, even trolls are sane), starts attacking the person doing the debunking on a personal level, behind anonimity…...I’m talking about the hurtful threatening language by a one David Parish and the supposed harassment of a young 13 yo blogger: +Arlen Moulton2  (his channel), by trolls of batteriser.

<deep breath>

Now before I start, this is not a game of throwing names, to be professional, you must hold your tongue sometimes, and if you must vent: refrain from insults, bad language and personal attacks.

Dave: I really don’t know how you take these insults, especially when they bring your family into it. You have my support! And to Arlen, keep at it dude, you have the support of me and others.

Back to +BatteriserOfficial . I don’t mind you selling your half baked idea, hell you could become like this guy: 

This is Gary Bolton: he sold those fake bomb detectors to governments all round the world - guess from this mugshot you can tell where he is now? He peddled a product that was not fit for purpose (admittedly, knowingly), duped governments (who should have really know better), with total disregard for the safety of millitary personnel, police and security men and women! (story on the BBC)

Now think about it: +BatteriserOfficial  are selling a product that from what the science says, is unfit for purpose…let me paint you a picture...

Take this scenario: Say somebody buys your product so they can, I dunno, use a torch for an emergency kit on a trip to a remote place. Emergency happens and they think the torch is good for “800%” longer. Time passes, the torch gets dimmer earlier than that person expects, they forgot to pack spares (why would they - these batteries are good for 8x longer right?).

Now its getting dark, with no other way to signal or see where they are going? They stumble through the dark, trip down a hole or ditch, fracture their leg, its getting cold, they're bleeding badly.....is their fate sealed or will somebody find them?

What the hell are you going to say to that person (or worse their family) when they come to you and say “My torch should have been good for 800% longer! I've busted my leg up and can't work! I'll loose my job and house!” or "My loved one put faith in your product and it let them down - despite thousands of people telling you your designing it wrong?! And now they're gone!" 

Let’s face it not everybody is an EE, so lay folks are going to make this mistake of believing your ludicrous claims! None technical or folk not interested in electronics don't want to hear about Amp-Hours, and voltages and currents - they just want a product that works!

So what’s your response?: "Sorry you  were in a life or death situation / lost your loved one, erm, would you like your money back?"

As with Gary Bolton, you may find yourself in front of a judge! The prosecution could have a case.

Going back to the insults From +Batteriser Batteroo  - how old are you? And do you really think your petty name calling is going to promote the company your following? Pretty damaging in my view. An  all behind a mask of a Channel and alias’s - tut tut - shame on you, least some of us have the good grace to put a face to our claims and voices.

I’m going to leave you with this thought +Batteriser Batteroo - when that person who has put faith in the claims your supporting and an angry customer does come knocking demanding a refund - and the next, and the next and the next, then a court summons appears through the door of Mr Roohparvar, will you be standing in the docks at his trail in support or will you be behind your computer, still slagging off the rest of the world?

</rant>

Hameg 203-6 repair: we have a lead! VB#4

So we have found the problem as to why its not working! Turns out my original assumption of thinking that because there was the right potential difference between the -1877V line and the -1900V line that there was indeed those potentials there.

But after thinking about it, I could measure the -1900V line by actually measuring the individual voltages across the potential divider network for the focus adjustment:

Turns out it came out A LOT lower than expected: 95V. That's way lower!

The problem only occurred due to a lapse in concentration. Usually, given that there are are high voltages flying round the timebase PCB and the back of the CRT PCB, I turn off the scope altogether and disconnect the mains whilst I have a think, take notes, and read the schematic. That's a pretty safe way of working. But this time I'd left it on and started to smell burning dust: that smell you get when the radiators are first turned on in your house after summer (ok people in temperate climates might not know what I'm on about).

Turning off the power, disconnecting the mains and then using the finger test found that IC501 - an opto-isolator - was very hot. Pulling it out and diode testing the diode emitter on it found it was very poorly, reading more ohmic than a semiconductor!

With the opto out, I thought why not test to see if I get the right voltages on the focus resistor network, and BINGO! Readings matched the calculations!

So next step is to order a replacement, double check that nothing else could have been taken out, and fit the new component.

Its very odd though - on day the opto's working and the next its dead!