Homebrewing

of both varieties!

Its been quite a while since I did much radio, so today I finally shifted the heap of spares and other bits off of the shack desk. A quick tune about showed the HF propagation to be next to nowt, so instead contented myself with finally working out the best way to connect my keyer and twin paddle key up!

This involved making up a custom cable, allowing me to connect the phono connector keying output on the keyer, to the screw terminal posts on my Kent straight key. This was a bit confusing at first, as the HF transceiver would go into Tx and stay transmitting! This turned out to be due to having the key line inverted!

A handful of test transmissions later and the keying is up and running. Ive also added four rubber feet to the twin paddle, which helps stop it sliding around the desk!

The other homebrewing ive been doing, was to start a 6 liter batch of Turbo Cider, and a tropical WOW wine. Unfortunately, this cost me more than expected, when I found that the ambient temperatures were too low, and had to invest in a heat tray! But the cider is now bubbling away merrily.

The WOW wine, is somewhat experimental. I have calculated the ingredients (sugar content) of this to drive a sachet of High Alcohol yeast to its limits. This should hit 18% ABV, if not more! It is also based on a tropical juice mix! Ive no ideal how it will turn out, but the must smelt and tasted amazing! I suppose I will know in a few weeks!

Tomorrow is the first performance of my youngest lads school Christmas show. There was something of a panic on Friday that the show would be without stage lighting, when it was discovered the DMX controller wouldnt work! A call went out for anyone with knowledge of stage lighting to contact the school...

...well, its about 20 years since I worked on stage lighting, and ive no experience of DMX, but I offered my services anyway, on the presumption that it would likely be a simple fault.

And indeed it was. The DC input socket had been flexed a bit too much and the PCB track at the positive socket pin has cracked.

Around half an hour in the workshop, and I had linked out all the power input connections to the nearest suitable solid connection. The school had their controller back, fully working, by the end of the school day.

Ive also finally been bothered to reconnect the power supply to my WSPR beacon. This I will leave on 40m for a while.



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LED Emergency Lights - Arranging for 12v supply

Apart from the need to test a number of individual LEDs on each of these Emergency Lamps, which are considerably dimmer than the others (so might need replacing from my LED stock), the big problem with repurposing these lamps is the need to arrange for the 3.9v constant currant LED array to be fed from a 12v source. The on-board 7135 current regulator cannot handle above 6v input, so I need an efficient way to drop 12v at about half an amp, down to between 4-6v for the current regulator.

I had planned on using 7805 linear positive 3-terminal devices, but using these to drop 8v at 500mA will consume 4W and they will get damn hot. Plus theres then the hassle of arranging smoothing and decoupling.

So, at the risk of having to wait for them to arrive from China, ive opted to go for pre-built Buck Converter modules based on the LM2596 device.

At under a sov each, I cant build them for this price! And being adjustable, I can set the output of the module to correspond with a sweet spot in the input range of the 7135 device. These devices, being switching converters, are considerably more efficient than the linear 7805, so should run much cooler.

I could probably arrange to trickle charge the 3.9v 1500mA NiCd packs in each lamp as well.


On each blog post  I will be including the following link -
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This is my own personal referral link, not an advert! I am with Bulb for gas and electricity. Do your own research, but if you decide to switch to them, do so via the above link, and we both get a £50 credit!

Brrrr Its bloody cold

Having had a sick little monster to look after today, ive not ventured out of the house, other than to check Milly the rabbits water and go to the recycling bins.

I had planned on going for a woodland walk with the camera, plus a little shopping, this morning, followed by an hour or two out with the detector in the afternoon. Instead, my car has now sat for 26h covered in ice, and will remain sat that way until 07:00 tomorrow - at which time, I will attempt to get it started for the quarter mile drive to the garage, where it is booked in to have the starter motor replaced! The failing starter is most unreliable when cold....

Im also mildy annoyed. I have, or rather had,  a couple of items on order from 7dayshop. I was hoping these would arrive tomorrow as they are part of a christmas gift. I discovered today that, without any word, they had cancelled and refunded my order! Apparently the items were out of stock - not according to the website when ordered!

A word to suppliers -
1) make sure your stock control algorithm works and update your webpages!
2) if you have to cancel someones order, at least put a note on saying why!

As it happens, I found a suitable alternative, despite not being offered one, and ended up re-ordering from 7dayshop, since they are still the cheapest, reliable supplier I know. I did also manage to find a voucher code, so got a couple % off, meaning I only had to spend an extra 70p or so.




On each blog post  I will be including the following link -
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Free fermentation bucket!

Someone at work brought in the remains of their kids Halloween sweets a while back, which came in a big tub. This was a 5kg Swizzles Party Pack

Once empty, I noticed it had a really good tight fitting lid, and was marked as food safe polypropylene. Hmmm, thinks me - I bet that has around 8 or so litres volume, would make a good fermentation bucket!

So, I 'claimed' it. Filling it one litre at a time with water, and marking it off, it turns out it holds 12L when filled right to the top.

I also noted a small, slightly thicker spot on the lid, perhaps something to do with the molding machine. Using a tapered drill bit, and a spare airlock as a gauge, I drilled a hole here until the airlock 'almost' fit, then proceeded to cut one turn at a time, until the airlock would push in snugly. 

Hey Presto! A 12L fermentation bucket absolutely free! Just in time to put on a gallon of Turbo Cider this week!

On each blog post  I will be including the following link -
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This is my own personal referral link, not an advert! I am with Bulb for gas and electricity. Do your own research, but if you decide to switch to them, do so via the above link, and we both get a £50 credit!

LED Escape Lights - Repurposing

My two boys have, for their play 'crib', a large shed. But this time of year they get little use from it, because its dark.

It just so happens though, that Ive acquired a pair of LED Emergency Escape Lights - the sort of thing you see over fire exits. Now, these are supposed to sit there, connected to the mains, keeping an internal battery charged, until such time as the mains fails, and then they illuminate for 30mins, to provide a guide for anyone attempting to escape a dark and possibly smoke filled building.

The pair Ive obtained each have an array of 27 5mm white LEDs, along with the charging and control circuit board and a 3.9v 1500mAh NiCd battery.

 Immediately, the possibility of converting these into 12v 'penthouse' lamps comes to mind. A 12v system is safe enough that I can let the boys have full control over it - so long as the supply is secure. In this case, the supply will be a large Sealed Lead Acid Battery, so all thats needed is a box.

The LEDs are arranged in parallel groups of three, each group with a 1ohm current limit resistor, on a single long PCB strip. The majority of the main PCB in each lamp is the mains switch mode inverter and battery charger circuit.

Most of the mainboards circuitry is therefore of no use for the new application. The only part that is, is the small black device in the center of the photo below

This is a 7135 Low Drop Out constant current regulator. Its job, is to provide a fixed 350mA drive to the LEDs. This works out at around 13mA per LED at 3v.

There is one problem though - the 7135 has a maximum input voltage of 6v! So, a further regulator, or other voltage dropping technique, is still required to bring the 12v supply down to within the 3-6v range of the 7135. Luckily, the industry standard 7805 1A 5v regulator, is incredibly cheap, and I likely have several in stock.



On each blog post  I will be including the following link -
 £50 credit if you switch energy supplier to Bulb Ltd
This is my own personal referral link, not an advert! I am with Bulb for gas and electricity. Do your own research, but if you decide to switch to them, do so via the above link, and we both get a £50 credit!