Sharp Vintage Calculators

My favourite calculator, the Sharp EL506. Really simple to use and no fancy "natural entry" nonsense that slows everything down in modern versions, with lots of extra keypresses required to do simple calculations. Cost me £5 in '84 when I started college. Batteries then lasted over 20 years.

"Talking Tools"

Just wanted to let you know about my new Facebook group "Talking Tools".
It's a platform for pros and newbies to talk about tools, share reviews and tips. Novices can ask questions and get help from more experienced members. Manufacturers can also show off their new products.

Talking Tools

Lawn Mower Won't Start? - Top 10 Small Engine Troubleshooting Tips

1. Use fresh petrol (gasoline). Old petrol can cause difficult starting. Make sure there is enough fuel in the tank and check the vent in the tank cap isn'tclogged
2.  The spark lead should be firmly attached to the plug, and the plug tightly screwed into the engine block. Try replacing the plug with a new one if the engine won't start
3. Most modern mowers have a control handle which needs to be pushed forwards/upwards and held in place to keep the engine running. Make sure this control is mower is held fully against the mower handle while starting.
4. If a manual choke is fitted, turn it on. Don't turn on the choke if the engine has been running in the last 10 minutes
5. If the engine has a primer bulb, press it about 5 times. If the mower runs out of petrol during cutting, it will need to be primed again
6. Check the air filter isn't dirty. Wash and dry foam type air filters in warm,soapy water. A paper filter can be blown out with an air compressor, but will eventually need to be replaced
7. Check the cable connecting the "dead man's handle" (the control which keeps the engine running when held in place) to the engine is not damaged or snapped
8. The carburettor should be tightly screwed or bolted to the engine
9. Make sure there isn't any water collected at the bottom of the petrol tank. If there is, drain the tank and use a piece of stick or long screwdriver with a piece of rag tied on (with a twisty tie) to soak up water
10. If the starter cord is hard to pull, check the underside of the deck and remove any clumps of grass which may be jamming the blade. Disconnect the spark lead before attempting to move the blade to remove clippings!

    

    Paper air filter

    
    

    

    Foam air filter

How Can the Pressure be Increased in a Shower?

If the shower is fed from a hot water tank, a cold water tank provides the pressure head to force out the hot water from the tank. This is usually in the loft to maximize the head so if it is located there, you are not going to be able to rise it any higher.
Cold water power showers are fed from the incoming mains cold water supply and the water is heated by a high powered electric element.
Shower heads incorporate a restrictor/aerator to reduce flow and water wastage. The Federal Energy Policy Act of 1992 made it a requirement that these were added to shower heads to reduce flow to about 2 gallons per minute, so removing this would increase the flow rate. Also it is possible to buy a shower head designed for a lower flow rate. This increases pressure but the flow rate will be less.
You can buy a booster pump which effectively works like a power washer and increases the pressure while keeping the flow rate constant.

How Can Hand or Garden Tools be De-Rusted?

Remove excess rust with steel (wire) wool soaked in lemon juice or vinegar which are mild acids. Rinse the tools and allow them to dry. You could soak the tools for a period to remove excess rust.
Another alternative which definitely works is phosphoric acid. This is often a constituent of rust removing chemicals and can also be bought in gallon containers from companies which supply cleaning chemicals. It is a powerful acid and can also be used for removing limescale from surfaces. Usually it is diluted with water before use. The objects being cleaned are submerged in the solution and should only be left in the acid for the bare minimum of time to dissolve the rust, otherwise the acid will start to dissolve the underlying metal! I have cleaned an old vice pillar drill vice belonging to my grandfather which developed a thick layer of rust after being exposed to dampness in a shed for over thirty years and the acid completely removed the rust.
Once you remove the rust, rub some oil into them and wipe off any excess. This will help to prevent future corrosion.
Sand can also be used as an abrasive for removing rust from tools.
If you wipe tools with light oil after use, it helps to prevent condensation and subsequent corrosion. Guns and tools were traditionally given (and probably still are) a coating of oil after manufacture and before packing to protect them from dampness and rust.

What Does the Voltage Rating of a Fuse Mean?

Image Courtesy, mtself CC BY SA 3.0 via Wikimedia Commons

The current rating of a fuse specifies the current which the fuse will carry without blowing. Once the current exceeds this value, the fuse will eventually blow. The characteristic of a fuse is such that if the current in a circuit is moderately higher than the fuse rating due to an overload, the fuse will take some time to blow, possibly seconds, minutes or tens of minutes, depending on the magnitude of the overload. If the current is a lot higher e.g. in the case of a short circuit, the fuse will blow in a few tens of milliseconds. While a low voltage or high voltage fuse will blow when the current exceeds the current rating, the current flow in a mains powered circuit can be extremely high (possibly thousands of amps) in a short circuit scenario because the current is coming from a large transformer outside the home. The breaking capacity of a fuse is specified in joules or kiloamps and a mains fuse could have a rating of 10000 amps or more. This is the maximum current the fuse can carry without rupturing. Usually fuses for mains equipment or distribution circuits have a ceramic body to withstand the heat and shock when the fuse blows. The fuse is also filled with quartz sand to absorb the heat and shock and quench the arc when the fuse blows. A glass fuse could simply rupture and possibly cause a fire if it carried such a heavy current. Glass/low voltage fuses may be used on the secondary side of the transformer in the power supply of equipment because the current output of the transformer in a short circuit situation is limited.

Good DIY Gifts For Men?

I better be diplomatic about this and suggest that DIY gifts for men needn't be any different than those which would be suitable for all the ladies amongst us (and even "non-ladies"!) Speaking as a serious male DIYer, I would like a cordless drill with two lithium batteries. The advantage of this battery technology is that the batteries don't lose their charge as quickly, and the drill is always ready for use.
A mitre(miter) saw is useful for making square cuts on timber, dado rail etc. An 8inch version is fine.
Jigsaws are useful for making curved and straight cuts in sheet timber. Go for one with variable speed on the trigger.
Angle grinders are useful for cutting metal and masonry.
A socket wrench set or ratchet wrenches(spanners) are always handy for tightening and undoing nuts and bolts.
Personally I would prefer to buy my own hand tools. While power tools are somewhat similar, the shape and size of hand tools are such that it is better to try them in your hand before buying. I mean how would a woman feel if their partner bought them shoes?

How to Reduce or Prevent Condensation in Your Home

Condensation occurs when air hits a cold surface. Air has a limit to the amount of water it can hold in suspension and the amount of water in the air is known as the relative humidity (measured as a percentage). Once air becomes saturated, the relativity humidity has reached 100%. Now as the temperature becomes lower, air can hold less and less water. Condensation occurs when water laden air hits a cold surface, reducing the temperature of the air. This could be glass in windows, cold tiles or metal surfaces. These surfaces are either colder than other surfaces in a room or are of high thermal conductivity so that heat is sucked out of the air. In any case, the air temperature drops to the extent that it can't hold moisture any more and it is deposited on the surface.
To avoid condensation you have several options. Firstly you can vent moisture laden air (e.g from cooking in the kitchen) so that it doesn't end up in rooms. You can do this by using extractor fans or simply opening windows. Portable gas heaters produce lots of water vapour and should be avoided. Another option is to raise the temperature in the room. This makes surfaces warmer so that moisture doesn't condense out. Double or triple glazing also helps because the external surface of inner panes of glass is not in contact with air outside the house. Removing sources of moisture also helps. This includes house plants and damp clothing. Clothes in the washer should be kept there with the door closed until they are transferred to a drier, or hung outside. Drying clothes in rooms or on radiators transfers water to the air where it inevitably condenses out if windows are closed and the room temperature drops. Yet another way of reducing condensation is to use a dehumidifier. This appliance works by circulating air over chilled coils. This causes moisture to drop out of the air (just like it does on your windows) and collect in a reservoir tank.

How Can a Freezer be Defrosted Quickly?

You can wipe over the ice with a cloth or towel soaked in hot water. This will soften the ice enough so that it can be scraped off. A plastic lifter like the type which is used with non stick frying is useful for getting in under the ice and prying it off. Don't use metal scrapers if the inner surface of your freezer has a foil coating as it can lead to damage. A basin of boiling water placed at the bottom of a chest freezer also helps to accelerate the melting of ice (After having pulled the plug and removing all food)

Why Do Computers Make Noises?

Several things in a computer make noises. First of all, the head in a disk drive makes some noise as it moves in and out over the aluminium platters in the drive during disk access. The head is actuated by devices called stepper motors which can rapidly move the head towards the center or edge of the disk. The motor which drives the platter/platters in a hard disk may also make some noise.
There may be one or more fans in a computer for cooling the electronics. The microprocessor (CPU) is likely to have a fan and there will also be a general purpose fan for drawing air through the machine to cool it. Usually there is a temperature sensor, and the fan cuts in and out as the temperature rises above and falls below threshold levels (just like the way an electric cooling fan for the radiator may turn on when a vehicle with the engine running is stationary for any length of time). Alternatively the speed of the fan may be varied, depending on the amount of processing of data which is taking place. It occasionally happens also on desktop computers when a fan gets old, the bearings can wear and the fan becomes noisy.
The power supply may also make some noise. When a current passes through electronic components, sometimes, electric or magnetic fields can cause movement (e,g, if you hold an older style, non switched mode, power adapter up to your ear, you can hear it humming). A sudden demand for power from the supply could cause clicking sounds.
Other clicking sounds can be caused by thermal expansion/contraction as the computer warms/cools (like the way gutters or roofs can creak when the sun comes out).
The old style dial up modem sounds were due to the "tones" which were sent down the line. Digital bits can't be sent directly down a phone line. Instead, various tones or sound frequencies were used to represent "ones" and "zeros".
As regards cooling fans, there is no harm installing a utility on your computer which displays the core temperature of the CPU or (CPUs if the machine is dual core or quad core). I have a utility called core temp installed which displays the temperature on the taskbar. It will power down the machine or display a warning if the temperature exceeds a set value. If you have a laptop, leaving it on a sofa can cause it to overheat, because the air intake may be under the machine and can get blocked. Another tip is to setup a laptop running on battery power so that it goes to sleep after a few minutes of inactivity.