Electronics and Embedded Programming V3

[Chryseus]

[QUOTE=MIPS;36857109]Something fell over last night and woke up everyone in the house.

...Fuck. I just got the flickering fixed on it too. :([/QUOTE]

Oh god I can't look at it, that poor TV.
Is that a glass plate over the front ? older TV's usually had these so as long as the tube intact you might be able to fix it.

[MIPS]

It's not a TV. It's a commercial grade plasma monitor. One of the original ones too. It's really old and built like a tank.
640x480 with BNC composite, Y/C and Sync on Green RGB inputs with serial control. It fell backwards and two bolt holes behind it pressed and cracked the tube. I spent several weeks fixing it. Plasma displays are total fucking rocket science.

[IMG]http://i11.photobucket.com/albums/a166/ballsandy/100_2805.jpg[/IMG]

[masterburner]

Oh man, what a shame to see that work of art go. :( Why did it fall over? Pets?

[DrLuke]

[QUOTE=masterburner;36867542]Oh man, what a shame to see that work of art go. :( Why did it fall over? Pets?[/QUOTE]

It probably was his Purple Crow.

[Chryseus]

Gentlemen I present to you a Philips B3G97U 1957 tube radio:

[img]http://i.imgur.com/X4ghu.png[/img]
[img]http://i.imgur.com/r08tG.png[/img]
[img]http://i.imgur.com/7osta.png[/img]

Also it works, the seller said it did not but I guess he did not wait long enough for it to warm up, aside from a possible dead FM band everything looks good, just need to clean up the case a bit more and it will be ready for a place on my workbench.

Yes those are stickers on some of the tubes, the paint started to wear off when I gave them a wash, as far as I can tell all but one are Mullard tubes made in England, one is a Tungsram.

I got kinda lucky with the buying it though, the seller did not provide a picture but I suppose that helped me since no one else wanted to bid on an unknown item.

I might put up some better quality pictures and audio tomorrow if anyone is interested.

[chaz13]

[QUOTE=LoneWolf_Recon;36854861]If you feel up to it you can further increase the cutoff by making a Sallen-Key Butterworth filter its essentially two low passes and a unity gain buffer smacked together. So if you happen to have a dual op-amp(I recommend the TL272CP). Then you can do this as well:

[URL="http://en.wikipedia.org/wiki/Butterworth_filter#Sallen.E2.80.93Key_topology"]Sallen-Key Butterworth - Wiki[/URL]

But, one thing at a time so go with Chryseus's recommendation first[/QUOTE]

Thanks for all the help.

Final questions (which will reveal just how little I know about electronics so far) I'm working on a little breadboard I just got, how do I go about creating the ground seen in all these circuits? Connect it to an unused part of the circuit?

(and a bonus question - I understand how the capacitor acts as a filter and how the resistor is just there to increase the time constant, but why does it need to be wired to a ground and not just in series?)

[Chryseus]

[QUOTE=chaz13;36874691]Thanks for all the help.

Final questions (which will reveal just how little I know about electronics so far) I'm working on a little breadboard I just got, how do I go about creating the ground seen in all these circuits? Connect it to an unused part of the circuit?[/QUOTE]

The ground symbol usually refers to the negative terminal of your power supply.

[Chezburger]

[QUOTE=DrLuke;36846943][img]http://upload.wikimedia.org/wikipedia/de/math/c/5/1/c51664193b423b008b1af8493cd22122.png[/img]

Pluck in your capacity and resistance and you'll find the cutoff frequency.

With some simple math you'll find that R = 1 / ( f[SUB]c[/SUB] * 2PI * C).[/QUOTE]

Does this work the same for radio frequent signals? I just wonder this.

[DrLuke]

[QUOTE=Chezburger;36876300]Does this work the same for radio frequent signals? I just wonder this.[/QUOTE]

Yes.

[Chryseus]

[QUOTE=Chezburger;36876300]Does this work the same for radio frequent signals? I just wonder this.[/QUOTE]

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.

[LoneWolf_Recon]

[QUOTE=Chryseus;36877558]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.[/QUOTE]

When that typically happens you go with this equation:

Cutoff Frequency = R / (2 * pi * L)

[chaz13]

[QUOTE=Chryseus;36874709]The ground symbol usually refers to the negative terminal of your power supply.[/QUOTE]

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!

[Chryseus]

[QUOTE=chaz13;36897065]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![/QUOTE]

Yes

[Chryseus]

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.

[img]https://lh5.googleusercontent.com/-24EKA8WV7ko/UA2aseC9VZI/AAAAAAAAA3I/O0B_MAmndbU/s1068/DSCF0576.JPG[/img]

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 > [url]https://plus.google.com/photos/101352201715170352622/albums/5768436123803387889[/url]

[chaz13]

That looks awesome! Where'd the radio come from originally?

Gave wiring the RC filter a go. Doesn't work, of course :v: 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).

[url]http://i45.tinypic.com/2eckq68.jpg[/url]

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.

[TTSDA]

-snip-

[VistaPOWA]

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 [url=http://www.taydaelectronics.com/]Tayda Electronics[/url].

[TTSDA]

[QUOTE=VistaPOWA;36905106]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 [url=http://www.taydaelectronics.com/]Tayda Electronics[/url].[/QUOTE]

Thanks for the tips! Removing that from the order, added some non-polarised caps.

[VistaPOWA]

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.

[img]http://www.electronic.hu/kepek/Szerszamok/Forrasztastecnika/TOOLCRAFT_ST-50A_forrasztoallomas.jpg[/img]

(if you guys in Portugal have Conrad, the Toolcraft ST-##A/D series is the best deal you'll ever get)

[TTSDA]

[QUOTE=VistaPOWA;36905299]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.

[img]http://www.electronic.hu/kepek/Szerszamok/Forrasztastecnika/TOOLCRAFT_ST-50A_forrasztoallomas.jpg[/img]

(if you guys in Portugal have Conrad, the Toolcraft ST-##A/D series is the best deal you'll ever get)[/QUOTE]

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.
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.

[VistaPOWA]

The Hakko FX-888 is also a popular model for beginners. Remember, this thing is a long-time investment.

[url]http://www.amazon.com/Hakko-FX-888-Soldering-Station/dp/B004M3U0VU[/url]

[DrLuke]

The Hakko is quite beautiful.

[Chipset]

[QUOTE=DrLuke;36906268]The Hakko is quite beautiful.[/QUOTE]

I think it looks like a toy, sorta like babies first soldering station.

[SubbyV-2]

Just bought this [URL] http://www.ebay.com.au/itm/9mm-x-100mm-Ferrite-Rod-/271017398430?pt=AU_B_I_Electrical_Test_Equipment&hash=item3f19e5509e#ht_3479wt_934[/URL]
Plan on hopefully winding a flyback transformer.

[masterburner]

With a straight rod? Good luck with that...

[LoneWolf_Recon]

[QUOTE=masterburner;36914599]With a straight rod? Good luck with that...[/QUOTE]

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.

[DrLuke]

It'll make a superb electromagnet though

[SubbyV-2]

[QUOTE=masterburner;36914599]With a straight rod? Good luck with that...[/QUOTE]

It still should work, Just not as efficient as a toroid, i hope anyway
[URL]http://www.ebay.com.au/itm/Power-Transformers-Round-Green-Toroid-Ferrite-Cores-75mm-x-39mm-x-13mm-/160840808986?pt=AU_B_I_Electrical_Test_Equipment&hash=item2572dbfa1a#ht_1853wt_1139[/URL]
Would this be a better option?

[POLOPOZOZO]

I'm not sure where to ask this, how much would a ZM1000 nixie tube sell for?

[Chryseus]

[QUOTE=POLOPOZOZO;36919350]I'm not sure where to ask this, how much would a ZM1000 nixie tube sell for?[/QUOTE]

£7 to £15