Electrical Project - Battery Voltmeter/Ammeter

Having four bikes (3 runners, 1 donor) means that some don't get used for long periods and I like to keep their batteries charged. A lead acid battery will self-discharge and I've had a flat battery freeze. (although it's rarely that cold here)

I use an old battery charger or a cheap battery tender that can be permanently attached. These don't give much indication of what is going on charging-wise. I can check the voltage being applied across the battery and the current flowing into it using a multimeter. But it's awkward doing this and it's easy to blow up cheapo meters by shorting them out across the battery on the current setting.

I thought that it would be good to have a device to measure voltage & current between the charger and the battery. A quick look on eBay found that such a device was available at a low price.

Now I'll say right here I not good with electronics. They are a bit of a mystery to me so I might start talking a load of rubbish.

The digital voltmeters/ammeters come in different ranges but I got a 100V/10A model.

It didn't come with instructions but I found a diagram on the internet.

The meter arrived from China yesterday and I made a unit to hold the meter, battery etc.

I tested it out using a fan.....

.....and it worked!

I hesitated attaching it to a battery. I was worried that if the charger was switched off the battery would discharge back into the meter and blow it up. The charger is protected by diodes so I fitted one to the meter. (a 3A Schottky Barrier Recifier if that means anything to you - 50p from Maplins)

The final arrangement with a battery being charged and the meter working.

A Short Run to Fife

It was a wet morning here today but it dried up later and the weatherman promised 12C/54F which is pretty much spring here. I headed to Fife on my CBF250, it was a short run but there was plenty to see.

Entering the Kingdom from the Kincardine Bridge

Longannet Power Station, now closed, burned coal mined in this area.

At Culross I passed this building. With its stone roof it looks like a dungeon but is the boathouse for a nearby mansion.

Culross is a well-preserved town with many interesting buildings. It was founded on mining. Coal provided the power for another industry - the production of salt.

This is the town "tron" or weighting scales. Goods would be weighted here before being loaded onto ships.

How things looked in days past.

Culross Palace dates from about 1600 and was built on the profits from coal. The red tiles are unusual for Scotland (slate being more common) but ships exporting coal & salt to Europe brought them back as ballast. The palace was getting some winter maintenance today.

The cobbled back streets were very bumpy!

Culross Abbey (1217)

In Charlestown there was evidence of another industry that used the local coal. These are lime kilns built around 1750. They operated until 1956.

The next town along is eh, Limekilns.

The Firth of Forth

In the town there were some classic cars outside the church. There seemed to be a funeral going on - for a car enthusiast?

The aircraft carrier HMS Queen Elizabeth under construction at the naval dockyard at Rosyth.

The Devil's Beef Tub

Today was sunny so I went for a run. It's still cool (7C/45F) but wrapped up well and with heated grips set to "high" it was quite pleasant. I went down to Dumfries and stopped at the Devil's Beef Tub on the way home. This is a hollow formed by hills at the end of a valley. The name comes from its use by the Johnstones, a local clan, to hide stolen cattle.

Panoramas of the Beef Tub

This a memorial to a covenanter shot by troops here in 1685

The CBF in Glencaple

Featured Bike - Honda CB750A (1977)

I saw this rare and unusual version of the sohc Honda 750 advertised locally on Gumtree. The "A" stands for automatic. This was a short-lived model fitted with automatic transmission. Well, semi-automatic transmission. It had no clutch but its two gears had to be selected manually. Drive was via a torque converter (like an automatic car) This fluid coupling meant that only two gears were required.

The bike has a mildly custom look and is different to the CB750 of the time. Note the lack of clutch lever.

The rev-counter is replaced with a dial showing gear position etc. The bike  had a parking brake on the rear wheel so it could safely be parked on an incline. There is a warning light for this.

The bike has a convential gear lever. Note "Hondamatic" badge.

A back-up kick starter is stowed under the seat.

The bike was on sale for £2,000 which seems reasonable given that it looks in good condition and that CB750s of this era are becoming collectable. I don't think this model was ever sold in the UK. Probably a US import.

Keeping the MOT Man Happy.....

....or eBay saves the day again.....or be careful in your purchases.

I took my CBF250 for its MOT (UK annual safety check) at the start of the year. It passed but Barry, the tester, said that I needed a new front disc. I admit to being a bit incautious with discs. So long as they aren’t warped and they stop the bike I'm happy. But on this occasion he had a point. The disc had severe wear. It gets a hard time because the bike is used in winter so exposed to dirt & grit etc.

Bike discs are pricey (£142 for a genuine Honda item or half that for a pattern part) but given the bike is in the autumn of its years I took a chance on a used part from eBay. Parts for the CBF250 are rare but luckily it shares parts with more common bikes. In case of the disc the CBR125 uses the same one. 125cc bikes are common in the UK because they can be ridden by learners, ie those who have not passed the test. Learners crash a lot hence plenty of parts.

I searched eBay and found a nice one for only £17. It arrived and it was indeed in good condition. I set about fitting it but hit a problem Although looking similar it had six mounting holes rather than the CBF's five. Damn! seems that different models of the CBR125 used different discs.

Back to eBay and I found a five hole disc, again in good condition, for a mere £12.

*ahem* - some wear was evident....

....the new one was much better

  

New pads

Old and new. Can you see the problem here?

Take two! - 2nd new disc fitted

  So if any wants a free Honda CBR125 front disc (6 holes) let me know.

Winter Portrait