I think he's looking for the photo resist chemical itself... Radio shack (and other electronic stores) sell pre-sensitized panels, developer, and etchant as a kit, but its expensive.<p>Look online, they are everywhere. www.injectorall.com is a place.
www.mgchemicals.com is another place.
Search found 26 matches
- Tue Oct 14, 2003 4:35 pm
- Forum: General Discussion
- Topic: Printed circuit photoresist
- Replies: 2
- Views: 2110
- Thu Sep 25, 2003 11:26 am
- Forum: General Discussion
- Topic: PCB developing
- Replies: 6
- Views: 3835
Re: PCB developing
There are two types of pre-sensitized pcbs, positive and negative. The positive pre-sensitized pcb is just what it says - what you see on the transparency is what you are going to get on your pcb after it is developed. The negative works vice-versa.<p>Now, with that said, you can print out your pcb ...
- Fri Aug 29, 2003 10:18 am
- Forum: General Discussion
- Topic: Debouncing Switches
- Replies: 7
- Views: 5703
Re: Debouncing Switches
Yes, you can do it in a crude way in the software...<p>btfsc PORTA, 0
call MyFunction
rest of code<p>
MyFunction
some code here
btfsc PORTA, 0
goto $ - 0x01
return
call MyFunction
rest of code<p>
MyFunction
some code here
btfsc PORTA, 0
goto $ - 0x01
return
- Tue Aug 26, 2003 3:28 pm
- Forum: General Discussion
- Topic: Measuring Resistance
- Replies: 15
- Views: 9586
Re: Measuring Resistance
This shouldn't be too difficult.<p>Since 1V = 1000 ohms, 8V = 8000ohms, you need a current source of 1V/1000 = 1mA.<p>That can be done minimally with a pnp transistor and two resistors. One goes to emitter and Vcc, the other goes to base and ground.<p>Then your current source equation would be I ~=V...
- Fri Aug 15, 2003 2:35 pm
- Forum: General Discussion
- Topic: PCB Layout, Strategies
- Replies: 3
- Views: 3330
Re: PCB Layout, Strategies
Thanks.<p>[ August 15, 2003: Message edited by: Lien ]</p>
- Thu Aug 14, 2003 9:44 pm
- Forum: General Discussion
- Topic: PCB Layout, Strategies
- Replies: 3
- Views: 3330
PCB Layout, Strategies
Are there any good books or sites on the net that give advice on PCB layout for best performance and minimal EMI noise for a switching power supply?<p>Also, is there info on analog circuit pcb layout in general?<p>I am getting more switching noise/ground problems on my switching supply than I expect...
- Fri Aug 01, 2003 9:00 am
- Forum: General Discussion
- Topic: Buying a digital multimeter
- Replies: 16
- Views: 7758
Re: Buying a digital multimeter
If you are just using it for hobby use and whatnot, then a cheap $5 meter would do... but if you're are involved in the ee field, then I would recommend a mid-level Fluke meter. Not only are they much more accurate, they also are well designed, have a host of USEFUL features, and the batteries on th...
- Fri Jul 25, 2003 9:34 am
- Forum: General Discussion
- Topic: Question about previous question
- Replies: 6
- Views: 3653
Re: Question about previous question
Yes, there's a product called Press-n-Peel that'll let you make PCBs with a laser printer. I've used it for simple projects and it works great, but with pcb tracks and spacing less than 20mils, you could have problems.
- Fri Jul 25, 2003 9:32 am
- Forum: General Discussion
- Topic: Need help with DC-DC conversion
- Replies: 11
- Views: 5194
Re: Need help with DC-DC conversion
Stephen pretty much hit the nail on the head.<p>To generate the PWM needed to drive the FETS, I would look into a TL494, or SG3525 IC. Easy to setup, easy to use, and easy to interface. Since you will most likely parallel a few FETS or use a big FET, I would look into a gate driver like an IR2110 to...
- Tue Jul 15, 2003 12:58 pm
- Forum: General Discussion
- Topic: AC/DC conversion to simulate car voltage
- Replies: 2
- Views: 2103
Re: AC/DC conversion to simulate car voltage
Since you didn't specify any requirements on the 12VDC power supply, I'll just say go buy one.<p>Edit: Nevermind, I didn't read your quote carefully... anyhow, take a look at linkswitch IC's, LNK501 and LNK500.<p>[ July 15, 2003: Message edited by: Lien ]</p>
- Tue Jul 15, 2003 9:04 am
- Forum: General Discussion
- Topic: ac/dc conversion and regulation
- Replies: 12
- Views: 6548
Re: ac/dc conversion and regulation
<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by IRONMAN: I agree with chris, the I.C. regulators are usually the cheapest most reliable way to go, however if you're talking about 24 VAC then be careful becuase when you run th...
- Fri Jul 11, 2003 9:40 am
- Forum: General Discussion
- Topic: Which Micro Controller to Choose?
- Replies: 9
- Views: 5434
Re: Which Micro Controller to Choose?
I gotta vote for Microchip also... the development platform for it is CHEAP and there are tons of resources available.<p>You can get a programmer for PIC chips for under $30. You can buy those chips at digikey for about $5 a pop.<p>The only difficult part is learning how the device works and its ins...
- Thu Jul 10, 2003 4:32 pm
- Forum: General Discussion
- Topic: Amp crossover
- Replies: 15
- Views: 7804
Re: Amp crossover
I'm designing and building an active 3rd order lowpass crossover for my subwoofer... it'll be adjustable for -3dB between 42Hz and 75Hz without affecting the Q too greatly. Of course, I can tailor the adjustment range to anyone's liking. If you're interested, shoot me an email. I have the majority o...
- Thu Jul 03, 2003 9:20 am
- Forum: General Discussion
- Topic: Mimicking tube behavior with solid state devices
- Replies: 5
- Views: 3305
Re: Mimicking tube behavior with solid state devices
Any more info available?
- Thu Jul 03, 2003 9:19 am
- Forum: General Discussion
- Topic: One-shot design needed
- Replies: 3
- Views: 2296
Re: One-shot design needed
I don't have my magazine in front of me, but in this month's issue of Nuts & Volts, there is a section on transistor circuits. In it, there are a few oscillator circuits that uses discrete devices, I believe with two transistors, a couple of caps and a couple of resistors.<p>Or you might want to...