/diy/ - Do It Yourself

OP, you can just buy a ready-made regulator off DX, they have either fixed 5V or adjustable ones. Some even have pre-soldered wires for the extra noob comfort.
If you need to charge Apple products, you will need the resistors in pic related.

>>663322
Perfect a whisker diode first, preferably using the lead glance mineral. Then place two whiskers right next to each other (you want less than 50um) and it will work as a transistor. But the maximum current will be low and the gain will be also terrible. You'll be lucky to prove it working with an LED and a resistor.

>>660282
I agree completely. I build things with logic gates, preferably CMOS4000. I used to do transistors, it's possible, but takes more time. I like to get things done and those gates are dirt cheap. Perhaps a better bang for the buck than the same circuit with discrete transistors.

OP, you will need a lot of power for this. I suggest that you use a gasoline motor for the mowing part and only use electricity for the driving. You should have 2 motors, each connected to both side wheels to imitate a tank steering. This way, you can turn without having turnable wheels like cars have. You would also benefit from some nice tractor tires because the stock plastic wheels on mowers won't get the thing moving far.
Use bicycle chains and sprockets to connect the wiper motors to the wheels. From there on, you will only need plain DC model regulators (intended for ships) and a pair of a transmitter and a receiver. You will need a plane/heli TX for this because a transmitter intended for cars may only have a steering wheel and a trigger which is no good for your "tank" steering. Unless that TX specifically has a "mix" (X+Y...X-Y conversion of the channels) built in.

>>436097
That glitch arose in a faulty video file, like mpg or avi. Then it was converted. The GIF itself, being an old format without non-key frames, can not do these effects. It merely freezes the animation or (very rarely) flashes with areas of solid color.

>>433714
OP, your best bet is to look into your motherboard's manual to find a jumper switch that changes the USB power supply. 5VSB is what you have now and 5V is the option you are trying to get. Each pair of USB connectors should have its own jumper for this. Even the front panel USBs which have it located on the bottom of the board near where the headers attach.
If you intended to make a working data USB port your way, you would probably fail to shield the data lines properly. It would be a mess.

OP, the schematic you have uploaded is very unsuitable for such long intervals because when you increase the time constant, the resistance goes way up and the capacitor will get drained through the B-E junction, never reaching sufficient voltages. That means no flashing.
For a much more linear and reliable circuit, you need something based on unipolar transistors. These have practically infinite input resistance, allowing you to choose your RC constants arbitrarily.
Google: cmos inverter multivibrator
and the first pic is your desired schematic, choose any CMOS that has inverters or inverting gates, 4069 sounds good.

I fix monitors with this problem regularly. Here is my advice:
You only need to change the bulging ones. Don't even think about touching the HV one to the right! These are already supplied good because skimping on it would result in a boom.
But here's the key trick to make your fix last: Place the replacement cap that's near the top in such a way that it gets far away from the heatsink. Make use of its original long leads; it should end up somewhere under the output pins. Put some tubing on the leads.
As for the value, the best is to use a step higher voltage rating. Your caps are probably 16V, so use 25V. Another helpful option is to use Low ESR caps.
Keeping the same voltage, but upping the capacity by one step (1000uF -> 2200uF) will also help because it reduces the ripples.

OP, the antenna type is reasonable, correctly polarized and for the right band used with digital TV. There are, however, all sorts of faults that ruin the signal. First, inspect all contacts that should be made by metal parts on the antenna. The V-shaped poles should be rust-free where they meet the central bus wires. Look at the impedance transformer PCB in the electrical box on the antenna. If it has any active components, like transistors, make sure that your TV sends out the right voltage to feed it. If you are less than 15 miles from the broadcasting tower, consider removing the amplifying PCB and refitting a passive impedance transformer. I know they used to be sold for this exact type of antenna here, not sure what's up now.
Redo the cable connection by any means.
Check the plugs attached to the cable anywhere on its way to the TV. Some plugs are notorious for fouling up the signal ever so slightly so that no fault would be seen with analog TV. Use a plug with robust screws with metal-on-metal threads for the center pin. Those tiny white plugs with set-screws in the plastic are a POS.
If you have splitters in the way of the signal, note that they are often the weak point and your best bet is to find what exact type does one of your neighbors have (assuming they have a good reception) and buy exactly that. The sellers are unfathomably brass so as to sell malfunctioning crap. Here, all-metal splitters are good while those tiny white plastic boxes disable digital signal almost entirely.

>>349633
It will probably need a symmetric 2×24V supply. You would have to have 4 batteries in series for that, with the center connection wired too.
Reconsider your inverter.

There was this weird Chinese microphone thing called PowerHear which would help you instantly, no soldering required. It has a built-in mic, a volume knob and a female jack output. Connect it to that Belkin digital FM transmitter and you got a sweet battery-operated wireless microphone.
But I have to say that it will whistle like hell it you attempt some live performance. The pros use dynamic microphones that have to be shouted at from small distance and the feedback wouldn't be as much of a problem.
vc: dionHo :)))

A metal tumbler is used to do exactly this. It will not make a mirror polish, but it requires no hard work and the surface will be uniform. Coat it with a clear varnish to protect it from fingerprints or it will tarnish soon.

The liquid for the lamp has to be slightly lighter than water or the wax will float constantly. What I did was to add about 10% pure ethanol to get the right density. But the resulting lamp didn't work as well as the original ones. I believe they also add in some kind of tenzide to help the wax blobs join easier. There is a ring of spring spiral at the bottom of the bottle, again to make the blobs join better.
The whole process is a PITA and you should just buy a finished lamp and don't fix it when it's not broken.

It probably tore off at least one of the metal pads. See where you can tap the PCB to gain the same connection. You may benefit from using a regular legged capacitor for this fix.

Yes, you have to reverse all polarized components including the power supply. Transistors are changed between PNP and NPN or N-channel to P-channel if they are MOSFETs.
But since this build is really cheap, I suggest you just buy the required transistors - and learn as much in the process as you can.
Ghetto mode: Find an old discarded device, solder out some transistors, use a multimeter to find your kind and its pinout and use that.

I can see your problem. Make the hole large enough so that a thin wire from a flexible cord along with the cap's leg will go through. Put the thin wire through the hole from the soldering side, make a tiny perpendicular hook, solder it to place so that you don't close the hole. Cut a bit from the back side. Insert the cap as closely as you wish. Proceed normally from now on.

>>292392
Stop being a willfag. Warts are caused by a virus and if they ever go away on their own, it's only thanks to the immunity system. They can also, however, eat through more important body parts under the skin and ruin tendons, for example.
I recommend anyone affected to visit a doctor ASAP.

Must be a photocell. You wouldn't measure voltage with a mere diode. But you must determine how many cells are in there in series. One cell gives 0.4V in bright sunlight, so take it outside and measure the voltage again. If it reads 1.6V, it means there are 4 cells inside. You can also salvage these from a used calculator, it is the purple glass tab. Don't mind the different design, just get the polarity right and it will work.

>>253796
If you have at least basic skills with electronics, do this: Connect a pair of headphones reliably to the output. Make a signal injector. If you are cheap, just take an MP3 player and a cable ending with a jack, hold the grounding of the cable with your hand and have the signal wire of any channel ready pointing out as a probe. You have the headphones on and you hold the wire with signal. Now when you touch the probe to the transistors' outputs (emitters if common collector), you should hear your music faintly. Good. Now touch it to the base of one of your power transistors. You should hear it significantly louder now. If you don't, there is your faulty component. Proceed backwards until you find the part which doesn't conduct your signal.
I once found a bad CMOS multiplexer this simple way in a seemingly very complex system.

>>250310
The first charge will indeed polarize it, but professionally made batteries have their positive electrode made of an alloy of lead and antimony and their negative electrode is a powder of lead and limestone pressed into shape. The electrodes aren't just sheet metal either, they consist of rigid grids of lead which have the required mixtures pressed onto them in the form of powder with needle-shaped grains. This increases surface and therefore capacity and maximum current.
I think that your plain sheet metal lead might work okay. But make as much surface as you can. If you get your lead in big chunks, melt it in a steel can, then pour the lead fast onto a large straight piece of sheet metal (probably zinc-plated iron). The lead will not stick to the sheet metal and it will form a sheet itself. You can then cut this lead stain into rectangles with workshop scissors.

>>244523
This. You can also shorten the tape without taking the case apart, just pull the tape out of one of the windows and do your work. Have clean hands and handle the tape carefully. Stick some clear stationery tape to the back of the tape, trim the edges to get the right width.
What I also used to do was to shorten the blank pieces of tape on both ends of the cassette to get even less silence, this way, I could have it playing as early as 2 sec from the start with all the brown tape still hidden at the end.

>>244530
I have similar problems, only perhaps less in severity terms. I have slightly more income than you, but I have been a virgin much longer.
I can only suggest that when you finally decide to "an hero," don't have a Heineken pack nearby or it will deter you. XD

In during "not your personal army".

>>236345
Start with a flat piece of high carbon steel that is just slightly larger than the outline of your knife. An old file is great for beginners because it can produce an incredibly lasting edge (compared to common stainless steel) and it is already a thin piece. Get it red-hot and pound a bit especially to compact the metal near your edge. Then use a power tool to create your desired shape including your primary bevel. After this, heat it up a lot (orange hot) stuck in a pile of black coal to prevent the access of oxygen. It is now more important since the grinding exposed the final edge parts that need to keep their carbon.
Quench it in water. It is also possible to pour water over the edge only with a teapot, but that technique is only good for very wide blades.
Then temper it in a kitchen oven. A good starting temperature would be 190°C. Twist it around for one hour in the oven because ovens don't have uniform temperatures inside. Then take it out and test the hardness. Scribe it with a regular file and feel the friction. It shouldn't feel like glass, you should detect some minor abrasion. If it feels like glass, raise the oven temp. by another 10°C and repeat until you can barely score it with a file. Then finish your job.