DIY-Central.com - Go Create something! - PCB Design, Electronics - DIY

This Is My Workflow When Designing A New Eagle Part Library I Like To Buy The Part Before

DIY-Central.com Administrator — Wed, 28 Jul 2010 19:59:14 GMT

This is my workflow when designing a new Eagle part library.

I like to buy the part beforehand, if possible. This gives me the chance to touch it and visually inspect the part and verify that the part dimensions match the working drawings from the manufacturer.

If working drawings from the manufacturer are not available, I use my digital caliper to make detailed dimensions of the part outline, and pin spacing and pin diameters.

If official PDF working drawings/datasheet are available, I use it though. Trust, but Verify.

Today, we're creating an Eagle part library for a switch.

Opening the datasheet, we look for the part dimensions.

In this case, we also take note of the switch positions, to see which terminals are connected depending on the switch position (up or down).

Next step is creating the schematic symbol for the part. In this case, an SPDT switch.

We also add "pins" to the schematic symbol. I use a "point" when defining pins on the schematic symbol.

I also like to match the "pin numbers" with the actual pin numbers used by the manufacturer.... makes life simpler.

Next, is creating the physical outline of the part. This is the FUN part for me. I like to make the part looking as authentic as possible. We also take care that we're following the part dimensions specified by the manufacturer. Don't forget to check pin spacings, and most importantly... pin DIAMETER. Since the PCBs will have plated through holes, I make the pad diameters just a hair-thin slightly bigger.

To make working easier, make sure to set your snaps and grid to 0.05" square, and 0.01" for the fine grid spacing.

And make sure holes/pads are centered on each "snap."

Make a print out your part and overlay the real part against your "printed part outline." Check if the holes, dimensions are correct and aligned. You may need several passes to get this right if you don't have official working drawings and just relying on caliper measurements.

If everything looks good, then we proceed to the next step.

Now, we tie together (match) the pin#s we created in the schematic symbol with the actual pin#s in the part outline.

This is also a good time to enter a part description field. I try to include Mouser or Digikey part #s in the description.

Next step is I try to use the new part library in a test schematic.

I want to verify that when I connect other components to this new part, that the correct pins correspond with the PCB design.

This is a good time to catch any errors you've made in pin-matching.

Here's our test schematic. R1 is connected to terminal #1 of the switch, R2 connected to terminal #2 and R3 connected to terminal #3.

Then we switch to the Board Layout view and verify that it's correct.

And we see that everything is OK. The pin #s in the schematic match the pin#s in the board layout.

In Eagle, the text ">NAME" and ">VALUE" are special. Eagle will substitute these text with the actual part name and part value in your schematic.

So in the symbol editor, let's add these text. Put the ">NAME" in the NAMES layer and put ">VALUE" in the VALUES layer.

In the Device Editor, click the Prefix button. Enter a prefix text.

Since this is a switch, we could use the prefix "SW" or "S". Now when you add multiple parts in your schematic, it will be renamed "SW1", "SW2", "SW3".... (Of course, you need to have ">NAME" present in the symbol, see step above.)

And we're done.

Low Wattage Guitar Amplifier Kits

DIY-Central.com Administrator — Mon, 04 Jan 2010 17:02:59 GMT

Featured above are working builds of the 8 Watt Ardmore and 1/2 Watt Gilmore Jr Kits designed by Gerhart Amplification tone wizard, Gary Gerhart. Everything is included except solder (use 60/40 rosin core solder, no flux). The chassis are finished for the Customer with all holes being drilled and punched. Note the stainless steel PEM nuts press fitted into the chassis for a solid, quality build. Kits feature a Mil-Std black anodize chassis, Mercury Magnetics power transformers, Gerhart Amplification's proprietary output transformers manufactured by Mercury Magnetics and all stainless steel chassis hardware. The assembly manual guides the builder through each step. The Gilmore Jr or Ardmore Kit are an excellent choice for those who are building for the first time, yet challenging enough for those who have built kits before. Guytronix stands poised and ready to assist the builder throughout the assembly process.

Click here for more details. http://www.guytronix.com/

TS-2 Rev.B Preamp Redesign

DIY-Central.com Administrator — Mon, 28 Dec 2009 23:04:46 GMT

A flash of inspiration... I found a smaller footprint output transformer I can use... so I created an Eagle part library for that. (Tip: use a digital caliper when creating part libraries)

After some creative rearranging of parts, and I made this.

This is just the motherboard. Measuring about 6" x 6".

Ch-check it out!

2 Input Transformers - NEW FEATURE
2 Output Transformers - NEW FEATURE
Gain and Trim knob for each channel
2 VU Meters
4 Full size XLRs
Relay Controlled switching - NEW FEATURE
Bigger DC Converters - NEW FEATURE
... and better PCB layout by re-arranging parts.

Also, reduced the number of molex connectors from the original (7) to a single 10-pin Molex! That will be a big time-saver.... plus the use of PCB mounted XLR Neutrik Jacks.

Sound Card Interface / AC RMS voltmeter Kit

DIY-Central.com Administrator — Thu, 24 Dec 2009 03:19:43 GMT

This looks like a very interesting project. If you're into audio measurements, this project might also interest you.

From the Pmillett website...

Most of us DIY audio types have been using PC sound cards to make measurements. There are excellent, inexpensive programs available to do test and measurement of audio equipment available. Personally I use Audiotester. If you've been around my web site you've seen FFT plots generated that way.

What has always been lacking is a decent interface between the sound card and the device under test (DUT for you geeks). There has been much discussion in forums like DIYaudio about this, and many proposals and circuits shown, but so far I've not seen anything implemented.

The problem with sound cards is that they are designed for fixed line-level inputs and outputs. Depending on the card this may be between 1V and 5V RMS maximum. They are also not tolerant of overloads - accidentally deliver 20V into your sound card input and you will most likely be looking for a new sounds card.

http://www.pmillett.com/ATEST.htm

TS-2 Mic Preamp Redesign

DIY-Central.com Administrator — Mon, 21 Dec 2009 23:40:15 GMT

I opened up a big box labeled "TS-2" that I've put away for sometime.
Surprise surprise!

I have lots of finished front panels, hundreds of blank VU meter boards, parts for the 48V DC-DC converter, inductors, chips, LEDs, etc... even found some brand new router bits.

I think I'm going to stick with the current front panel design. So we'll have power on/off switch, VU meter on/off switch, 48V on/off, polarity reverse switch, gain, and trim knobs and 5-LED VU meters. This design is as basic as I can make it (while still keeping the features working.)

I think I've got the solution now to reduce labor building a TS-2 preamp. The new board design will:

Reduced molex connectors from (7) to (2).
Eliminated 12 wire to XLR soldering tasks.
Eliminated 12 wire stripping, and 12 heatshrinking tasks.
Made easier soldering the VU meter PCBs to the main motherboard.
Eliminate 14 wire stripping, 14 molex connectors crimping tasks.

I think I can have a prototype PCB for the new board design by late January. So I need to finish the PCB design before the 31st.

Wifi Radio

DIY-Central.com Administrator — Mon, 21 Dec 2009 17:32:49 GMT

Mightyohm documents in his blog the making of a low cost, open source wireless streaming internet radio receiver. All construction details, including schematics, source code, and even the design process itself will be documented on this blog. http://mightyohm.com/blog/2008/10/building-a-wifi-radio-part-1-introduction/

Doing Some CNC Milling Work After A Couple O

DIY-Central.com Administrator — Sun, 20 Dec 2009 03:43:41 GMT

Doing some CNC milling work...

After a couple of hours, I have these babies...

For my TS-2 preamps

TS-2 Preamp by FiveFish Studios

DC-DC Converter How-To

DIY-Central.com Administrator — Sat, 19 Dec 2009 20:10:27 GMT

Maxim offers a great explanation of DC-DC converters.

DC-DC Converter Tutorial

Abstract: Switching power supplies offer higher efficiency than traditional linear power supplies. They can step-up, step-down, and invert. Some designs can isolate output voltage from the input. This article outlines the different types of switching regulators used in DC-DC conversion. It also reviews and compares the various control techniques for these converters.

http://www.maxim-ic.com/app-notes/index.mvp/id/2031

DIY Audio Synths

DIY-Central.com Administrator — Fri, 18 Dec 2009 14:34:39 GMT

You want things that make bleeps, noises, and other electronic noises? Then this kit is for you!

Bleep Labs Robo Audio Synths

Enjoy making all sorts of robotic and electronic noises with this light-controlled analog synthesizer.
Great fun for the hobbyist, musician, electronics buff, or goober who just likes making weird noises for people.
1/4" output jack to connect to guitar pedals, amps, etc. (no input jack)
Thingamakit features two LEDacles and has square and triangle wave output which, coupled with the secondary photocell, means even more creative and sound control.
Thingamagoop includes: one Thingamagoop (your choice of color) - each will have slight (very slight) sound variations as each is hand made.
Thingamakit includes: Detailed instructions., fully labeled components, simply laid out circuit board with minimal hand wiring, two ready to blink LEDacles, "stompbox" style enclosure, and control panel and face stickers.

http://www.thinkgeek.com/electronics/musical-instruments/bf12/

DIY Microphones

DIY-Central.com Administrator — Thu, 17 Dec 2009 14:24:57 GMT

This site http://scotthelmke.com/ showcases a lot of DIY microphones by the author. They look awesome. Here's a picture of a stereo microphone.

This mic is based on a pair of Transound TSB-55A cardioid electret capsules. These capsules are almost identical to the Panasonic WM-55A, but with a bit flatter low end. The two capsules are in a vertical stack, splayed out about 100 degrees. I really designed it to fit into a grand piano for live sound, but it does a nice general stereo recording as well.

I've also built stereo mics with the bigger, better Transound capsules. Those tend to be quieter, but not as flat as the TSB-55A.

Construction is a lot simpler than it looks. The body is just 1" ID copper water pipe, with the window cutouts done with a Dremel tool. The screen is brass mesh from McMaster-Carr. The capsule mount was made from various bits of brass from that little craft-metals display in the hardware store, and is mounted in a wooden plug that fits inside the mic body. Finally, the connector is a Switchcraft B4M, which fits the copper pipe almost perfectly. I used a piece rigid tubing to help the body of the connector fit nicely into mic body. This mic uses a small external power supply which is phantom-powered from a standard audio mixer. It would also be possible to build a simple power supply using a 9 volt battery and with an 1/8" stereo output, for use with a minidisc or other small recorder.

http://scotthelmke.com/stereo-mic.html

More DIY Microhones... http://scotthelmke.com/microphones.html

Portable Preamp TS-2 Redesign

DIY-Central.com Administrator — Thu, 17 Dec 2009 14:16:09 GMT

The TS-2 has been getting some traction recently... and I'm thinking maybe it's time to revisit this product again and do a Revision B.

The first TS-2 design was very good, and I love the sound of it! (Of course, it's based on the SC-1mk500 and SC-1mk2 preamps, but in a smaller form factor.)

But assembling a single TS-2 unit takes up a lot of time/manpower and with the small profit I have on each unit, it's a losing proposition. I'd come out ahead if I DON'T build a TS-2!

So to fix this problem, I'd need to raise TS-2 prices, or reduce my production cost, or a little bit of both. For now, I'm going to concentrate on reducing production cost. With today's economy, it may not be smart to raise prices (unless that price increase brings with it additional features that the original TS-2 didn't have.)

Question: So what can I do to reduce production cost?
Answer: Reduce the time/manpower to build a TS-2 unit.

Question: How can I reduce time to build a TS-2 unit?
Answer: Good question...

I'm thinking of several possibilities.
1. Through automation. Using SMD parts and pick and place machines. Ask a manufacturer to build the boards for me.

Cons: A little on the expensive side, and requires a lot of capital. I think 100 boards is the minimum. Assuming it will cost $50 per board assembly fee, 100pcs is a staggering $5000!

And I doubt it will cost only $50 per board... maybe closer to $100. And that's just the labor. The cost of parts for 100 boards is not included yet.

2. Minimize "wiring". Yes, soldering wires to the PCB board and connectors, and jacks take a lot of time. So if we can get rid of "flying wires", then that will reduce a lot of time and labor. So as much as possible, use PCB mounted jacks, switches, LEDs, etc... everything should be soldered to the PCB. No more hookup wires, if I can avoid it!

3. Reduce the number of PCBs. Right now, the original TS-2 preamp has 4 PCBs. A motherboard and a switchboard, and 2 VU meter PCBs.
That's a lot! And of course, there are hookup wires to connect all 4 PCBs to each other (see #2 above). So I need to reduce the number of boards required to build a TS-2.

I've upgraded my PCB design software last year, to allow me to make the bigger boards. Unfortunately, the TS-2 board design was prior to my software upgrade.

Now, with the ability to make bigger boards, I think I'll be able to combine more functions in a single board.

We've got plenty of real estate space FREE!

What else...

Revision B will also give the user the option to have INPUT TRANSFORMERS! So that will be cool! Maybe even add a switch to bypass Input Transformer. Hmmm... I'm getting too far ahead here.

So that's my goal.... redesign the TS-2 preamp to minimize wiring, combine more functionality in a single board, and add some new features.

DIY Tube Microphone

DIY-Central.com Administrator — Wed, 02 Dec 2009 14:54:33 GMT

A DIY Tube Microphone.... and yes, it's a KIT! What's even more awesome about this is the microphone body, grille and other stuff is included in the KIT. Anybody that's into building DIY microphones know this is the most hardest thing to DIY... the microphone case. Not the electronics, not the power supply but the mechanical enclosure! So this kit packages everything nicely.

From the writeup:

Beautifully machined (unpainted) brass microphone body and head-grill assembly
Internal mounting cage assembly to mount circuit board, capsule, transformer and connector housings.

Components included

1 - 32mm/1in large diaphragm pressure gradient capsule (assembled)
1 - Plastic capsule mount
1 - Pre-amp circuit PCB
1 - Tube socket PCB
1 - Vacuum tube, 12AX7
1 - 9-pin tube socket
1 - 7-pin XLR male connector
2 - Ceramic insulators for both ends of C4

1 - Film Resistor, 1/2 W 10KΩ
1 - Film Resistor, 2W 100KΩ
2 - Film Resistor, 1/2 W 270KΩ
2 - Resistor, 51M
1 - Resistor, 200M
1 - Film Resistor, RJ 1/2 W 3KΩ
1 - Resistor, 1 KM
3 - Capacitor, 1μ/400V
2 - Capacitor, .022μ/630V
1 - Capacitor, 1000 pF/630V
1 - Capacitor, 100μ/25V
3 - Capacitor, 0.1μ/63V
1 - Capacitor, 1000μ/10V
1 - Ceramic Capacitor, 2pF
1 - Transformer, turns ratio 10:1

1 - Fully assembled power supply
1 - Power cable for power supply
1 - 7-pin microphone cable

Printed documents
Schematic

I bought this kit on eBay and sure hope to find the time to build it. I'll post pictures of my build.

FiveFishStudios - X-12mk500 Lunchbox (API 500 Series) Preamps

DIY-Central.com Administrator — Mon, 30 Nov 2009 14:41:57 GMT

Last October, I held a sale of my X-12mk500 preamps.
http://fivefishstudios.com/index.php/X-12mk500-Mic-Preamp-Kit.html

These are some of the units that went out to customers... <drool>

Thanks to all my customers that support FiveFish Studios DIY Mic Preamp kits.
Some photos:

from another angle

X-12 Preamps in a 1u rack case.

DIY-Central.com Administrator — Fri, 02 Oct 2009 03:49:22 GMT

Lunchbox pres racked in a 1u case

Just a test.... checking clearances, and how the whole thing will look.

The real deal will be a setup for (2) X-12 pres.

update:

Finished X-12 preamp, 2 channel in a 1u rack.

check it out... We now have audio samples of the X-12 Mic Preamp.

http://fivefishstudios.com/index.php/Audio-Samples.html

Special thanks to Farview Recording (Jay Walsh) and Jason Mallow. You guys ROCK! Also thanks to Madison Rhoades for the vocal clips.

Check out the Servant song... all tracks recorded through an X-12 Mic Preamp.

SC-1 Lunchbox preamps racked in a 1u case

DIY-Central.com Administrator — Fri, 24 Apr 2009 14:26:24 GMT

SC-1mk500 Lunchbox pres racked in a 1u case. If there are any interests in this configuration, email me at info@fivefishstudios.com

X-12 Mic Preamps now on SALE

DIY-Central.com Administrator — Sat, 28 Mar 2009 15:25:10 GMT

The X-12 preamp kits are now on sale.

I updated the X-12 PDF guide and explained more about the option of using PDIP8 chips and DOA chips.

The key is using MillMax socket pins on the board. This will allow you to quickly remove the PDIP8 chips, insert your DOA chips and do some listening tests. The DOA chip sits well above the IC sockets. You'd have to remove the PDIP chip though if you want to use DOAs.

Here's the latest photo of the X-12 preamp using an API 2520 clone Discrete Op Amp.

X-12 Mic Preamp with Discrete OpAmps 2520 style

DIY-Central.com Administrator — Sun, 01 Mar 2009 15:24:17 GMT

More photos showing discrete opamps installed on the board. You don't need to desolder the 8pin IC socket. Just install the MillMax sockets and the discrete opamp will install with enough cleareance above the IC socket. (You'd need to remove the PDIP8 IC chip.)

with a JFET-992

with APP2050 (Made in Italy)

with APP10 (Made in Italy)

X-12 Mic Preamp Kit

DIY-Central.com Administrator — Fri, 27 Feb 2009 15:22:44 GMT

This preamp was inspired by A certain Preamp Indeed!

But no, it's not a clone. Rather, I'd like to call it my FiveFish version

It uses input transformers with high-nickel and mumetal shielding, monolithic opamps and also has the option to use 990/992/2520 discrete opamps, null offset, output transformers, on-board voltage regulators, Relay-controlled -20dB Pads and Polarity Reverse, Soft-start phantom power, LED-lighted push button swithes, Grayhill selector switch, Bourns pot.

It uses a very very low distortion opamp chip for amplification, coupled to a high current, high-slew rate (2000V/us) video buffer driver subjecting that output transformer into submission.

The sound is huge and beefy... it will fight back when pushed hard, and slap you up and down silly to let you know who's boss... kinda like a rock n roll club bouncer.

(VU meter not shown in above photo, 5-LED VU Metering included in kit.)

White vs Yellow fill paint

DIY-Central.com Administrator — Sat, 20 Dec 2008 15:30:14 GMT

What looks better? I can't decide. Help me.

The white paint fill "pops out"... and is very clear and bright. But seems drab and lacks personality.

The yellow has "personality" and not boring like white. But I'm not sure if I like the yellow.

These are Testors model paint by the way.

NEW SC-1mk2 Mic Preamp Kit with Input Transformers

DIY-Central.com Administrator — Sun, 16 Nov 2008 15:33:29 GMT

SC1-mk2 Mic Preamp Kit

Now, with optional Input Transformer option!
Improved design, improved performance, design refinements.
Uses the same "footprint" as the original SC-1, so you can use this new kit in our 1u SC-1 Rack Case.
Have 2 channels of clean/uncolored preamp and 2 channels of "flavored" preamp
Local PSU regulation for a 2nd-level filtering of power supply.
DC Servo, Dual Buffered design
THAT and Burr-Brown chips
Using uMetal shielded Input Transformer for excellent magnetic shielding
6dB gain steps in the lower range, and 4db gain steps in the upper range for more precise control
Using standard 0.1" pitch pads for power and XLR connections, Molex 0.1" compatible
Bourns, conductive plastic potentiometers
Grayhill, mil-spec selector switches
0.079" thick PCB with 2 oz. copper, Solder mask, silkscreen, plated-through holes, Lead-free Rohs

More ordering choices, more package deal combinations for better discount!
Flexible ordering with or without PSU, Rack Case, Input Transformers, etc... to fit your DIY budget.

More photos: