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Post #1361
Yes.
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As DrLuke said yes, however at higher frequencies (above 1MHz) parasitic capacitance and inductance also become very important so care needs to taken to ensure parasitic effects are minimal and avoid undesired resonance.
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When that typically happens you go with this equation:
Cutoff Frequency = R / (2 * pi * L)
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In this case it's supposed to be a passive circuit.. so would I connect it to the negative terminal of the jack socket the signal is coming from? Thanks for all your help!
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Yes
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I've been working on the radio chassis today getting a lot of the old dirt, dust and oxide off the metal and other parts so it looks significantly better, I've almost finished my parts order, turns out Farnell is the only supplier that stocks the capacitors I need so I'm going to bulk order a lot to make it worth it.
There are no major technical problems at the moment other than the FM possibly being a little weak and some random pops and hum in the audio, the case needs a little cosmetic work done as well and a new light bulb which illuminates the tuning indicator.
Once this is done I think I'll get an RF signal generator (vintage) so I can calibrate the radio, although it seems accurate at the moment that may change when I start replacing parts.
Oh and in case you're wondering where the tuning capacitor is, there is none, this radio is permittivity tuned with sliding ferrite cores which move in and out of the inductors.
Also the labels on the tubes are temporary, some of the lettering got washed off when I gave them a clean.
More pictures > https://plus.google.com/photos/10135...36123803387889
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That looks awesome! Where'd the radio come from originally?
Gave wiring the RC filter a go. Doesn't work, of course
Here's a picture, any obvious problems? The things on the left and right at 6.5mm jack sockets, and the long thing is potentiometer that goes up to 500 ohms. The capacitor is 47uf.. I've order some 1uf ones but I thought I'd use this just to check it does something but it appears to have no effect.
I'm not sure if that's because it's wired wrong, or because of the values (but I believe the lowest cutoff should be around 6000Hz which should be ok).
http://i45.tinypic.com/2eckq68.jpg
pic
EDIT: Got it working! woooo! thanks to everyone who helped. Still not sure why my mono sockets have two pins ANd a ground, but hey ho I'm not going to complain.
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-snip-
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You might want to get some non-polarised capacitors too, and some jumper wire (Choose the strands of single-core wire instead of the premade jumpers). Also, that distance sensor seems like a total ripoff.
You won't need 5 relays.
I suggest that you get LEDs from eBay and ICs, such as voltage regulators and logic stuff from Tayda Electronics.
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Thanks for the tips! Removing that from the order, added some non-polarised caps.
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If you don't have a soldering iron yet, don't buy one of those which you plug into mains and operate at one single temperature. I'd suggest you spare some more money and buy a soldering station like one of these. The default tip that you get with soldering irons, the pointy tip is totally useless when it comes to electronics and you should buy a chisel tip with it if you want your first soldering experience not to be a nightmare.
(if you guys in Portugal have Conrad, the Toolcraft ST-##A/D series is the best deal you'll ever get)
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I was planning to buy a soldering station, but I didn't know of that model, thanks for pointing it out, it's probably going to be what I will buy.If you don't have a soldering iron yet, don't buy one of those which you plug into mains and operate at one single temperature. I'd suggest you spare some more money and buy a soldering station like one of these. The default tip that you get with soldering irons, the pointy tip is totally useless when it comes to electronics and you should buy a chisel tip with it if you want your first soldering experience not to be a nightmare.
(if you guys in Portugal have Conrad, the Toolcraft ST-##A/D series is the best deal you'll ever get)
About the tip thing I already knew it because I saw the EEVBlog series on how to solder.
Thanks for your help!
EDIT: Aw, Conrad doesn't ship to Portugal. I will have to find an alternative.
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The Hakko FX-888 is also a popular model for beginners. Remember, this thing is a long-time investment.
http://www.amazon.com/Hakko-FX-888-S.../dp/B004M3U0VU
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The Hakko is quite beautiful.
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I think it looks like a toy, sorta like babies first soldering station.
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Just bought this http://www.ebay.com.au/itm/9mm-x-100...#ht_3479wt_934
Plan on hopefully winding a flyback transformer.
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With a straight rod? Good luck with that...
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Best to use a toroid, so that you don't waste your magnetic flux. As well as affecting whatever electronics that are in the rod's way.
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It'll make a superb electromagnet though
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It still should work, Just not as efficient as a toroid, i hope anyway
http://www.ebay.com.au/itm/Power-Tra...ht_1853wt_1139
Would this be a better option?
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I'm not sure where to ask this, how much would a ZM1000 nixie tube sell for?
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Ł7 to Ł15
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Holy hell that's like $30 in real people money!!
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I made a switchmode PSU out of a motor and 555 timer. I also tried to give it a cutoff at a certain voltage, but that didn't work out so great, I think the op-amp was frilled.
The motor was spinning by the way, without it spinning it goes up to 24V (with a 10 kOhm load).
How can I make it more powerful? Smaller inductance? Right now I can barely get any juice out of it.
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Check this PDF out: Buck Converters Demystified
I made a switchmode PSU out of a motor and 555 timer. I also tried to give it a cutoff at a certain voltage, but that didn't work out so great, I think the op-amp was frilled.
The motor was spinning by the way, without it spinning it goes up to 24V (with a 10 kOhm load).
How can I make it more powerful? Smaller inductance? Right now I can barely get any juice out of it.
You maybe saturating the inductor(Especially since you are using a motor)
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Another recent project (shitty quality deal with it):
Now I'm sure there would probably be a WAY easier way to go about remotely shutting down a computer but I don't care - this was kinda fun.
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Why not get a bunch of russian ones off ebay? They're next to free.
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Yes, that would be much better. A closed core would give you much better efficiency and more current. I would stick to ferrite cores though (like the one you have in that link), because they saturate more easily than iron core transformers, giving you some current limiting.
The efficiency of an air gap transformer is absolutely terrible. Even a small slot in a closed core transformer completely messes up your efficiency. But feel free to experiment with efficiencies, now that you have both cores. Would be an interesting experiment.
Also I want to apologize for my previous reply. It wasn't particularly helpful...
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How about winding it for a flyback? how would you suggest i do this?
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Who said anything about buying them muahahaha
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How could I go about changing my rc filter to a second order one?
I know you just add a second filter effectively, but it's currently controlled by a potentiometer.. I can't add another potentiometer because that'd just be silly so how can I have it so one will control both parts of the filter?
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The easiest solution I think is to get a stereo potentiometer. That's basically 2 pots on the same shaft.
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I made a little 24v supply.
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It's so cute.I made a little 24v supply.
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Can we see the inside?I made a little 24v supply.
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Yes.Can we see the inside?
Nothing special, will replace the thin wires at some point.
Thanks for providing me with a box to put the supply in, DrLuke.
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Where did you get the case from?
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Overpriced conrad, almost as bad as sparkfun (except their solder + soldering stations).
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So I ordered 50pcs of 2W resistors, and instead got a single 50W resistor. Atleast it has the same value. It should come in quite handy when I need to test a PSU or something.
Also my 20m of stranded 10mm˛ wire arrived. I'll use it to wind a proper primary coil for my tesla coil, which should eliminate most of the problems I had.
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My 60W hot glue gun arrived from DX so I decided to put it to use, since we all like power supplies:
Made in England top quality.
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