• Electronics and Embedded Programming V3
    1,545 replies, posted
[QUOTE=Chezburger;36168260]So...much...interesting...projects.. Why do I need to make my own Yagi-antenna in order to continue my research program on homebuilt tv transmitters.. In other news, I bought a kit of some Audio/Video modulator, and will build it in in a 19" rack with proper filtering and an amplifier to serve as a transmiter that could cover the whole block with Chezburger-tv. UHF is mad fun when you're at it[/QUOTE] Have fun getting a license and other stuff to transmit legally :v:.
fuq da polies No, in all seriousness, my creations generally do not create more then 250 mWatts of power, I am not the big kWatt pirate you'd encounter in the east, merely a lone attic engineer. I do consider getting my N and F license for operating a Ham radio set though, then gettin' one of these [IMG]http://www.g3ngd.talktalk.net/ft-101e.jpg[/IMG] Oh and by the way, if any of you have these fuckers in storage: [IMG]http://www.electronix.com/images/rf7.jpg[/IMG] Let me know, I am highly interested in UHF Modulators, especially if there origins are old VCR sets. Btw, ddrl, didn't you take apart some old set some time ago? I remember a photo with a nicely looking modulator in the pile of rubble that came out of it!
[QUOTE=Chezburger;36169736]fuq da polies [IMG]http://www.g3ngd.talktalk.net/ft-101e.jpg[/IMG] [/quote] Excuse me while I clean my pants. Oh and yeah I still have the modulator, got another one at a trade show a while back as well. Edit: Here it is! [img_thumb]http://i.imgur.com/pCTcZ.jpg[/img_thumb] It contains: TDA5330T (VHF, UHF and Hyperband mixer/oscillator for TV and VCR 3-band tuners) TSA5511 (1.3 GHz Bidirectional I²C-bus controlled synthesizer) :flashfap:
My turn to clean my pants. The source of the aetherial hell I am creating this time is no common modulator found in VCR sets though, I bought a Velleman K4601, thought it would be a nice step up to working with modulators! Now I have to figure out how to build a low pass filter for 500 MHz :o [editline]2nd June 2012[/editline] I am quite familiar with the TSA5511, have a bunch in storage here. I use them in the set RDVV FM Transmitters, dutch design, ofcourse! Speaking of that transmitter, I need to finish it once. Just like my homebrew frequency counter, Anyone else tends to finish projects later on?
[QUOTE=Chezburger;36172649]My turn to clean my pants. The source of the aetherial hell I am creating this time is no common modulator found in VCR sets though, I bought a Velleman K4601, thought it would be a nice step up to working with modulators! Now I have to figure out how to build a low pass filter for 500 MHz :o [editline]2nd June 2012[/editline] I am quite familiar with the TSA5511, have a bunch in storage here. I use them in the set RDVV FM Transmitters, dutch design, ofcourse! Speaking of that transmitter, I need to finish it once. Just like my homebrew frequency counter, Anyone else tends to finish projects later on?[/QUOTE] I usually start putting something together with loads of enthusiasm and then give up because I'm lazy. Still need to finish repairing my Philips PM 3200...
Ah, good ol scope, I asked my chaps at the technical department at my school if I could get some of their old Hameg HM103 scopes, those things have been tortured. So I began a retirment home for tortured testing gear. [editline]2nd June 2012[/editline] Gotta head back to school next week to pickup a casettedeck, it will be given a second life in the radio-communications lab of Chez, lets hook it up to my faithful Kenwood R-1000. Everything is lovely once again.
ITT post your "ongoing" projects. -1 AA cell keychain emergency phone charger -motorizing my window blinds and curtains + adding control via web ui -6v Lantern battery modded into portable battery powered adjustable lab power supply with custom fallout 1&2 style Micro fusion cell label -building shelves (cause electronics hobby takes up space) -adding led lighting to said shelves -making said led lighting solar powered -3x3x3 led cube (soldered the cube already) -ATX psu to bench power supply mod (done but I need to add dummy loads to achieve atx spec minimum load to stabilize outputs) -adding a LED door bell to my room door because when listening to music I don't always hear people knock -building MOT powered linear power supply for burning stuff up -building a "proper" adjustable bench power supply -building a rudimentary signal generator (sine wave, some hz to a few hundred khz nothing fancy) -modding a pc into an aluminium suitcase (tried to buy one today but the one I wanted was sold out :C ) -making a 30A ish current load for testing power supplies (don't even know where to start on this one) -finding a use for my two RF transmitter-reciever pairs (one at 25mhz I think and one at 430mhz I think) -making a (couple of) decade resistance box(es) -buying a new multimeter (been putting this off for so long it's starting to feel like a project of its own) Pretty sure that's it, will add if I think of any. Post your own lists!
-Finishing 4-Bit Computer -Building Bench-Top Logic Power Supply -Testing some 300K pixel cameras for a possible robotics project in the future -Wanna get a new multimeter soon(or atleast some new fuses for my current) -Needing to fix up that old FM transmittter I made months ago -Gonna test an instrumentation amplifier for a brain wave project with a friend Thats bout it.. :/
Keep me posted on that transmitter of yours. HF high five yo. For me it isn't that much -0.1 MHz - 1.0 GHz frequency counter (damn you and your exotic components) -5 Watt FM transmitter -15 Watt FM transmitter - Rev up the freshly created UHF oscillator - finishing the beginning of an LC meter - stereocoder print I really want to go on with inventing and learning in the RF but the money man the damn money, considering that I still need more "basic" shit like frequency counters (not the homebrew stuff, but a bench model) The holy grail remains spectrum analyzer.
If I made a full list of everything I didn't finish, it'd make me depressed. I much prefer just to consider anything I haven't worked on in a while abandoned forever and forget about it. Right now I have three things I'm working on occasionally: 1. A mouse benchmarking rig 2. The "binary static mesh" (BSM) model format 3. My game engine (ongoing experiment, I don't ever expect to finish)
- Adjustable bench power supply, linear, 0-30V 1A - Transistor curve tracer, network analyser - High voltage supply for tubes, linear or switchmode *working on now* I try keep my list of projects small, that way they stand a chance of being worked on at some point.
- Tesla Coil - ATMega32u2 breakout/dev board - Hacking into my bike's dynamo to build a sort of bicycle computer - HeNe laser PSU
[QUOTE=Chryseus;36174687] I try keep my list of projects small, that way they stand a chance of being worked on at some point.[/QUOTE] I still have that problem, fortunately the to-do list is helping that.
I have a problem, my button leads wont reach across the column to the other side of the bread board they are too short, should I solder on longer legs?
[img]http://i50.tinypic.com/24o4mit.png[/img] That moment when you notice you don't have any trimming-potentiometers left
[quote]ITT post your "ongoing" projects.[/quote] -Calibrate and reassemble plasma screen -Reassemble and test CRT projector -Build enclosure for said CRT projector -Buy insulators and install shortwave antenna -Install weather station -Reorganize house circuit breakers for 240 breaker -Have above electrical work signed off so the switch can be flipped -Complete troubleshooting tape drive power supply. It's somewhere on the primary side, I know it. Otherwise, why else would the primary caps read only 73v? -Recap all my damn cameras which use those shitty ass SMD capacitors [QUOTE=Chezburger;36169736]fuq da polies No, in all seriousness, my creations generally do not create more then 250 mWatts of power, I am not the big kWatt pirate you'd encounter in the east, merely a lone attic engineer. I do consider getting my N and F license for operating a Ham radio set though, then gettin' one of these [IMG]http://www.g3ngd.talktalk.net/ft-101e.jpg[/IMG] [/QUOTE] I always saw ham as such as hassle. The equipment even used and sometimes older than you is only ever for sale for absurd prices and to get the license is a royal bitch. I'd probably just buy a ham from a scrap dealer one day and run it on some frequency that seems clear enough to stay under the radar of the ham-a-days who report you if you say "ass" over the air. Pirate TV sounds cool though, especially since you get to foul up the spectrum of the now dead UHF. Speaking of RF. I setup a [url=http://i11.photobucket.com/albums/a166/ballsandy/100_2838.jpg]clothesline pole[/url] in the backyard and made it so it could accomidate my shortwave antenna which is pretty much a length of copper wire. I need something to connect the antenna to my Heathkit shortwave radio. Would 75 ohm TV cable be okay? In other news, I made a flexible PCMCIA adapter so I could build an Orinoco wireless B card into a toughbook. [IMG]http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/100_2839.jpg[/IMG] [IMG]http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/100_2842.jpg[/IMG] [IMG]http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/100_2843.jpg[/IMG] [IMG]http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/100_2844.jpg[/IMG]
[QUOTE=MIPS;36175558]*Every time MIPS posts content*[/QUOTE] So much win and awesome.
Here is my todo list: - constant current sink (up to 500 watts) - frequency counter with ZM1180 nixies and CMOS counters/latches - to build a clock with some HUGE 7 segment displays I got from some trade show (30cm in hight) - solid state tesla coil (currently gathering material for this one) - 3 axis cnc router (all mechanical work is done, I only need to paint it and stick all the electronics in a pretty box) - ODB2 analyzer - CRT tube clock with an old, large radar tube I've got - USB lab power supply (that is a power supply fed by USB, just like the EEVBlog one) - Curve tracer for my scope ([url]http://www.vego.nl/3/1/6/3_1_6.htm[/url] ) The CNC router is currently eating up all my time. I now need to buy a bunch of connectors to connect the machine itsself to the control box.
[QUOTE=masterburner;36179955] - to build a clock with some HUGE 7 segment displays I got from some trade show (30cm in hight)[/QUOTE] I want to do the same, I was going to build the 7-segment displays myself using a bunch of LED bars meant for computers. Gigantic.
[QUOTE]Pirate TV sounds cool though, especially since you get to foul up the spectrum of the now dead UHF. Speaking of RF. I setup a clothesline pole in the backyard and made it so it could accomidate my shortwave antenna which is pretty much a length of copper wire. I need something to connect the antenna to my Heathkit shortwave radio. Would 75 ohm TV cable be okay?[/QUOTE] Pirate TV is where the fun starts, it's however a tad more complicated than FM, about that antenna, I'd go with your standard RG58 50 ohm coax, at least that is what I have used ever since, and I use an inverted v antenna so it'd be alright. [editline]3rd June 2012[/editline] That receiver of yours looks quite sturdy, I like it!
I kinda feel like building a gyroscope, but I have no idea how to get electricity to the core.
I just cleaned out my workbench, took apart the area formerly known as "The Graveyard". I guess no one can tell me what shit ended up there.
Got my high voltage switchmode boost converter supply designed and working nicely with regulation. [b]Schematic[/b] [t]http://i.imgur.com/gvixP.png[/t] [b]Output Voltage[/b] - reference potentiometer set to 1V [t]http://i.imgur.com/HrVDC.jpg[/t] [b]Output Ripple[/b] - with minimum load [t]http://i.imgur.com/3jLrq.jpg[/t] [b]On Breadboard[/b] [t]http://i.imgur.com/Fe5m1.jpg[/t] [b]Parts used[/b] Q1 - 2N3905 Q2 - E13007F2 (from my previous salvage operation) D1 - 1N4007 U1 - KA258 dual op-amp M1 - 2N7000 Rest as show on schematic. Using 555 to generate 10kHz square wave which comes in at V4. Not exactly the worlds best but it does the job very well, I've tried powering a 40V motor and a 100-250V switchmode supply without problem. [url=http://www.mediafire.com/?8nh4tbvjct8nk18]LTSpice schematic[/url]
[media]http://www.youtube.com/watch?v=vWBKKpL_AhA[/media] I replaced the normal RC receiver in my RC car with an Arduino and a Bluetooth modem. I guess this is nothing compared to the kind of stuff you guys do, but I'm really happy I got it working without breaking any components and even did a bit of soldering.
[QUOTE=Chryseus;36181974]Got my high voltage switchmode boost converter supply designed and working nicely with regulation. [b]Schematic[/b] [t]http://i.imgur.com/gvixP.png[/t][/QUOTE] I'm interested in how the feedback loop works (specifically M1). You seem to cut off the input from the 555 timer when it exceeds the voltage threshold, which makes perfect sense, however it seems odd choice to me. Don't switch-mode supplies usually adjust the duty cycle of the waveform rather than further modulating an already modulated waveform? Wouldn't that give you finer control and less variance in the output? Or is your method simpler? Also, if you're using the op-amp as a comparator in a feedback loop, shouldn't you add in a little tiny bit of hysteresis just to ensure that it never reaches equilibrium?
[QUOTE=ROBO_DONUT;36183914]I'm interested in how the feedback loop works (specifically M1). You seem to cut off the input from the 555 timer when it exceeds the voltage threshold, which makes perfect sense, however it seems odd choice to me. Don't switch-mode supplies usually adjust the duty cycle of the waveform rather than further modulating an already modulated waveform? Wouldn't that give you finer control and less variance in the output? Or is your method simpler? Also, if you're using the op-amp as a comparator in a feedback loop, shouldn't you add in a little tiny bit of hysteresis just to ensure that it never reaches equilibrium?[/QUOTE] Yes variation of the oscillator duty cycle is usually the preferred method of regulation in switchmode power supplies, this method is kind of the brute force approach and while it does work the overall efficiency is poor and introduces quite a large amount of output ripple. Adding a little hysteresis seems like a good idea, I'll have to do some more testing. Maybe I can take advantage of the 555's control pin and convert it to duty cycle control.
[QUOTE=ROBO_DONUT;36183914]I'm interested in how the feedback loop works (specifically M1). You seem to cut off the input from the 555 timer when it exceeds the voltage threshold, which makes perfect sense, however it seems odd choice to me. Don't switch-mode supplies usually adjust the duty cycle of the waveform rather than further modulating an already modulated waveform? Wouldn't that give you finer control and less variance in the output? Or is your method simpler? Also, if you're using the op-amp as a comparator in a feedback loop, shouldn't you add in a little tiny bit of hysteresis just to ensure that it never reaches equilibrium?[/QUOTE] -snip-
Blurry since low light (damn 3w led spotlights) [t]https://dl.dropbox.com/u/59112523/shelves/2012-06-03%2020.02.04.jpg[/t] Woop, shelves! Same ikea model that Dave uses in his lab but I picked the 60x120 shelves (his are 40cm deep) for lods o estorage space. The shelves are way deeper than they appear in the picture. Just after taking this pic I hooked up the computer, gonna start moving in equipment and tools soon.
I suggest you buy even more shelves. Mine are always full before I know it... Can never have enough shelves.
I love those moments that bring out your evil laugh. [img]http://eagle.undo.it:8083/img/cdwelder_10_somethingwicked.jpg[/img] Shit makes big sparks. Not sure what to call this model, maybe "My Little Capacitive Discharge Spot Welder"? [img]http://eagle.undo.it:8083/img/cdwelder_10_frontpanel.jpg[/img] From left to right, we have: power switch, 3-way charge/do not charge/discharge switch, rotary voltage control, capacitor voltage readout, 1/4" TS connector (with a tattoo machine foot pedal attached). It is just a little bigger than a Nintendo Gamecube [img]http://eagle.undo.it:8083/img/cdwelder_10_overview.jpg[/img] I'm glad I made those electrodes detachable, because if you screw around welding unsuitable materials, the electrodes hold fast to the material. Because the electrodes are easy to remove, working them on the bench grinder is a breeze - don't underestimate that 6 gauge wire! Was "fun" putting it together. Wish I used a fan for [i]all[/i] of the soldering, because the fumes are making me dizzy. [img]http://eagle.undo.it:8083/img/cdwelder_10_inside.jpg[/img] In retrospect, I'm not too sure if all these fast-ons were a good idea. [img]http://eagle.undo.it:8083/img/cdwelder_10_top.jpg[/img] Now, time to rebuild a shit-load of battery packs!
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