Well, the title may be bit confusing, i dont tell about recycling paper files/folders, but instead, i thought it would be good to share this info, if someone is interested .
So, i found that my loved paper file/folder (what is it called anyways in english, book-like thing you put papers inside to keep them organized?) decided to break apart. Nothing big, but the mechanism bended over, so it didn't serve well anymore. Normal people would throw it away, and buy a new one. But what i did, thought a moment, ''any further use for this?'' and bingo, i took it more apart, salvaged; couple stiff enough cardboard pieces to be used as cutting/drawing board, not smooth thought. Handle that shuts mechanism, would make great bended chisel, only needs handle and sharpening. And small bars where you put papers, make good clothes or other hangers, only threads needed and base to install them. YES i may sound bit cheap about all this .
Due to nice weather, i decided to take little tour to local recycling center, havent been there a while. It seems it was indeed worth it, as i bought another typewriter, AEG olympia mastertype 100i, for 5 euros. Last one was indeed great find, and as it turns out, this was too, even better. And, in WORKING condition.
Last on had safety-earth, this didn't have such luxuries, but there are no metal parts much to be earthed either, so 230v socket was euro-style, 2-pin.
Power boards transformer has much more windings, and ffiltering caps are same brand as earlier, also, fuses of course. control board has 74 family logics, motor control IC:s, couple memories and cpu's of some sort, lockable mini-ide connectors, power resistors and discrete components. PCB at ink cassette assembly has bunch of connectors, opto-coupler plus power resistors & lockable mini-ide connector. Couple more opto-couplers were found at ink cassette too, and paper roll has one too. Again, solenoid
My tower fan stopped working, so i figured i should take a look at it. it was surpsing hard to open in the end, but was made possible, nothing broke up.
Repair itself: At first, nothing really showed up, no bulged caps or anything else sucpicious at first. I measured the voltage pins for transformer, and it turned up to be okay. Then, when i plugged it, somewhat bigger spark came from dc-socket. I measured supply voltage pins for controller chip, 5v as datasheet says, so at least it gets supply voltage. After that, i realized that couple of smd-transistor were pretty warm, hot actually, so i measured them just to make sure they are not SC/OC, they turned out to be just fine. But, then i felt AHA, when i saw possible fault. One of the caps leads were left too long, and it was bent over to wrong place, causing SC. No wonder there was spark at dc-socket. I snipped feet smaller, and 'voila, repair success. Also, i noticed couple bad solderings, which i repair too. Well, i
Just simple circuit, but i found it quite entertaining and educating to do, figured it would make good post too.
So, idea is simple: Fan speed controller with ''speedmeter''. Fan is basic 12VDC computer fan without PWM I/O pins, only +/- wires. But it's still controlled with PWM fashion, made my 40106 schmitt trigger, connected as variable PWM controller. At alone, this isn't strong enough to drive fan, so N-fet, IRF540, takes care of this. Also, fet has necessary pulldown resistor on its gate, to shut it down during off-time.
Next stage is ''speedmeter''. Actually, it isn't speedmeter straightforward, but duty-cycle meter. First, there is low-pass filter, along with opamp,lm358 which converts PWM/frequency to voltage, cind of DAC (digital-to-analog?). After that, analog signal is fed to led-driver opamp, i used lm324 quad, which acts as comparator, different levels to different leds.
That's pretty much all to it, feel free to comment! .
Simple circuits for amplifying a LM35 or LM335 temperature sensor output for use with an ADC.
Following on as part of this remote "monitor" gadgets I’m playing with, it would be good to use a single cell (battery) to power the remote devices. In the past some cool step-up devices form Pololu Robotics & Electronics: NCP1402 and S7V7F5 (both shown below).
These allow using a single AA or AAA battery to power +5V devices and fit within the regular footprint of a TO-220 regulator. But I also must include with them the case to hold the AA or AAA battery. So upon further research I found a really neat reference design from Microchip using their MCP1640: MCP1640 Single Quadruple-A Battery Boost Converter Reference Design.
That is so simple, small, and elegant; I figured I had to give that a try. Now I don’t use AAAA-size batteries, but if they did such cool stuff with a smaller size (and packed more complexity), I had to be able to
As part of this concept I’m working on to “monitor” several gadgets remotely using the home router and some sort of wireless “gadgets”, I settled for 433MHz devices. I had some OOK receivers and transmitters which I used in the past, so I decided to start with those.
These are basic ones from either Radiotronix (now Linx Technologies), Wenshing (through Sparkfun), or Laipac. For reference, these are the modules I’ve worked with; but pretty much any standard OOK (or ASK) module should work.
• RCR-433-RP (Radiotronix)
• RCT-433-AS (Radiotronix)
• RWS-371 (Wenshing)
• TWS-BS (Wenshing)
• RLP 434A (Laipac)
• TLP 434A (Laipac)
To use them you modulate the data input with a TTL
Hi, because schools electric lab moves to different place, they cant take all stuff with them. So teacher gave me this function generator because my lab lacked proper function generator. it works like charm, no need for repairs or anything .
it has sine/triangle/square wave, adjustable from 0.2hz to 2Mhz, 1/10/100/1k/10k/100k/1M push buttons set range. voltage depending from load from 10-20v. output impedance is 50Ω
connector are BNC with shell connected to safety ground. Connectors consists of: input VCF, output TTL/CMOS(both only square wave) and normal 50Ω output.
Dc offset +10 to -10, +5 to -5v @50Ω load. attenuation -20db is selected form amplitude switch.
And their adjustment knobs, with pullout switching between features.
Case is held in place by 4 screws from bottom. Back panel has only connector to mains cord. See photos for interior, what i like about interior is that there are no SMD, just personal opinion. I did
I have a 3-yr old Sagem router which had behaved well until the last 6 months or so, when I began getting intermittent on-screen messages saying there was no Internet connection. I thought little of it and put it down to the vagaries of the Internet. Yesterday, however, the failed connection seemed permanent.
Investigation showed the router trying repeatedly (and unsuccessfully) to reboot, accompanied by arcing sounds from its wall-wart. I had heard these sounds on a few previous occasions but attributed them to mains spikes. Clearly the wall-wart had problems. Replacing it with another got the router behaving properly, with no obvious signs of damage, confirming the fault lay in the wall-wart.
So, nothing ventured nothing gained and judicious use of a hacksaw and lever soon got the faulty wall-wart casing apart. Nothing inside looked cooked, apart from one of the tinned-copper straps linking the SMPS pcb to the mains plug pins. As soon as I moved it slightly it fell away
Just an update of my flea market visit:
well as usual, i went to flea market to test my luck. at first, nothing really caught my eye, but i did find computer PS/2 mises, both ball and analog models dirt cheap IMO, 0.5 € (50 cents) per unit!. considering what is inside of single mise; micro switches, cables, opto-components and maybe some other things, not bad find. Well i took all of 'em, total of 12 pcs. Also, i found 4w/230v fluorescent night lamb at 2€, but its lamp is broken . Inside of lamp was |/0/|| selection rocker switch, and surprisingly, control/ignition board. Board consists basic electricity stuff, mains fuse, caps and stuff. There were also couple nice details also, like NE555 timer, probably for PWM modulation of some sort, and TRIAC Motorola AC97AB.
And wirewound resistor 10w/100Ω. For now, diode on board is mystery, is it light-sensing diode? board has marking CDS on it.
I took photos from fluorescent lamp, and made schematic, if you