Title: What homemade test gear have you built and still use?
Post by: NiHaoMike on October 01, 2012, 05:02:21 am
Post by: NiHaoMike on October 01, 2012, 05:02:21 am
What homemade test gear have you built and still use?
I built a bench power supply about 10 years ago. It is basically an old tape drive power supply (5V, 3A and 12V, 2A) along with a dead bugged 0-18V, 3A linear power supply both housed in an old AT power supply case. To this day, it's still the bench power supply I use the most.
I also have an isolation transformer I made about 5 years ago by disassembling two 120W halogen lamp transformers and reassembling one with two primary coils.
I'm currently building an inductance meter. I already have a working prototype on a breadboard, but I'm working on putting it into a cheap multimeter case. I'm planning on entering it into the 7400 contest since it's based on a single 4049.
I built a bench power supply about 10 years ago. It is basically an old tape drive power supply (5V, 3A and 12V, 2A) along with a dead bugged 0-18V, 3A linear power supply both housed in an old AT power supply case. To this day, it's still the bench power supply I use the most.
I also have an isolation transformer I made about 5 years ago by disassembling two 120W halogen lamp transformers and reassembling one with two primary coils.
I'm currently building an inductance meter. I already have a working prototype on a breadboard, but I'm working on putting it into a cheap multimeter case. I'm planning on entering it into the 7400 contest since it's based on a single 4049.
Title: Re: What homemade test gear have you built and still use?
Post by: arakis on October 01, 2012, 10:20:16 am
Post by: arakis on October 01, 2012, 10:20:16 am
Plz post pics of you r cool devices :)
I built a DIY soldering iron controller, uses a 1n14007 diode as a sensor attached near the tip, simple comparator to switch a relay with power on and off to the heater... It's ugly as hell ( everything is cases in a Nesscoffe can)... it's also unreliable as hell, has to be constantly adjusted:)... but it did solder everything I trew at it for 4 years ;)
P.S. I won't be sharing the pics, as A I don;t have a camera worth a dam, B: it's ugly as hell:)
I built a DIY soldering iron controller, uses a 1n14007 diode as a sensor attached near the tip, simple comparator to switch a relay with power on and off to the heater... It's ugly as hell ( everything is cases in a Nesscoffe can)... it's also unreliable as hell, has to be constantly adjusted:)... but it did solder everything I trew at it for 4 years ;)
P.S. I won't be sharing the pics, as A I don;t have a camera worth a dam, B: it's ugly as hell:)
Title: Re: What homemade test gear have you built and still use?
Post by: voidptr on October 03, 2012, 10:15:34 am
Post by: voidptr on October 03, 2012, 10:15:34 am
this is a kind of my homemade test gear :oP
i build this thing, really usefull, very affordable, can be bent in any shape, alot more usefull than the third hand thing everybody buy ( i got one of those third hand in the bottom of of box somewhere ) ...
this one is brand new ! built yesterday, i lost my old one ...
i build this thing, really usefull, very affordable, can be bent in any shape, alot more usefull than the third hand thing everybody buy ( i got one of those third hand in the bottom of of box somewhere ) ...
this one is brand new ! built yesterday, i lost my old one ...
Title: Re: What homemade test gear have you built and still use?
Post by: voidptr on October 03, 2012, 10:39:54 am
Post by: voidptr on October 03, 2012, 10:39:54 am
:o)
im still an electronic noob but there is still one old thing im still using time to time ...
i built long time ago small testbench with 10 SR latch unbounced switches, less useful now
with those handy microcontrollers littles boards.
but still i used it last week for manually blipping one signal :-)
i put it in the last year 7400 contest but i didn't win :o(
pfffff ! i don't care i still love it :oP
http://http://dangerousprototypes.com/forum/viewtopic.php?f=62&t=2967
im still an electronic noob but there is still one old thing im still using time to time ...
i built long time ago small testbench with 10 SR latch unbounced switches, less useful now
with those handy microcontrollers littles boards.
but still i used it last week for manually blipping one signal :-)
i put it in the last year 7400 contest but i didn't win :o(
pfffff ! i don't care i still love it :oP
http://http://dangerousprototypes.com/forum/viewtopic.php?f=62&t=2967
Title: Re: What homemade test gear have you built and still use?
Post by: sqkybeaver on October 03, 2012, 03:17:43 pm
Post by: sqkybeaver on October 03, 2012, 03:17:43 pm
[attachment=0]
not the leads but the rack they hang onto, made out of sheet metal from some scrapped electronics, this keeps all my leads from wanting to curve and avoids massive snarls.
not the leads but the rack they hang onto, made out of sheet metal from some scrapped electronics, this keeps all my leads from wanting to curve and avoids massive snarls.
Title: Re: What homemade test gear have you built and still use?
Post by: bearmos on October 05, 2012, 07:19:03 am
Post by: bearmos on October 05, 2012, 07:19:03 am
[quote author="arakis"]P.S. I won't be sharing the pics, as A I don;t have a camera worth a dam, B: it's ugly as hell:)[/quote]
Oh come on, the ugliness is half (if not most) of the fun ;-)!
...keep that in mind when looking at this junk...
A thrown together workbench (in use for ~ 6 years now. originally built using an upturned recycling bin as a saw horse). I need to cut a hole in the back of the shelf so I can fit an old analog scope up there.
[attachment=5]
home-brew LED lamp replacement for the $30 fluorescent bulb that burned out on my scope. It's using the crazy form of AC from the fluorescent light ballast - it took some trial and error to get the right voltage drop across the LED's because of this (I know nothing about driving fluorescent lights).
[attachment=4] [attachment=3] [attachment=2]
A light box with some terrible diffusion (still useful for lining up double sided artwork and tracing):
[attachment=1]
[attachment=0]
More to come, I'm maxed out on the number of attachments.
Oh come on, the ugliness is half (if not most) of the fun ;-)!
...keep that in mind when looking at this junk...
A thrown together workbench (in use for ~ 6 years now. originally built using an upturned recycling bin as a saw horse). I need to cut a hole in the back of the shelf so I can fit an old analog scope up there.
[attachment=5]
home-brew LED lamp replacement for the $30 fluorescent bulb that burned out on my scope. It's using the crazy form of AC from the fluorescent light ballast - it took some trial and error to get the right voltage drop across the LED's because of this (I know nothing about driving fluorescent lights).
[attachment=4] [attachment=3] [attachment=2]
A light box with some terrible diffusion (still useful for lining up double sided artwork and tracing):
[attachment=1]
[attachment=0]
More to come, I'm maxed out on the number of attachments.
Title: Re: What homemade test gear have you built and still use?
Post by: bearmos on October 05, 2012, 07:27:53 am
Post by: bearmos on October 05, 2012, 07:27:53 am
Breadboard power supply (5V, 12V). Switching supply salvaged from an old external HDD case and put into a project box. There are also some breadboard "modules" including an LDO (this was before you could buy them from places like adafruit ;-)) and a microchip programming header.
[attachment=4]
[attachment=3]
And a pieced together "lathe". . .well. . .something that may slightly resemble and early ancestor to a lathe - it spins. . .
[attachment=2]
And it has a precision speed control (quick clamp on the trigger):
[attachment=1]
The results were a whopping 1/16" accuracy - almost completely unusable. . .almost
[attachment=0]
[attachment=4]
[attachment=3]
And a pieced together "lathe". . .well. . .something that may slightly resemble and early ancestor to a lathe - it spins. . .
[attachment=2]
And it has a precision speed control (quick clamp on the trigger):
[attachment=1]
The results were a whopping 1/16" accuracy - almost completely unusable. . .almost
[attachment=0]
Title: Re: What homemade test gear have you built and still use?
Post by: matseng on October 05, 2012, 07:56:46 am
Post by: matseng on October 05, 2012, 07:56:46 am
Seeing Bearmos breadboard in the previous reply I realized that I should show two of my modded solderless breadboards:
The first is really old - so old that I thought it was a good idea to have a dedicated TTL->RS232 converter mounted on it. The blob to the left contains a MAX232 and the capacitors for it.
[attachment=4]
[attachment=3]
The second has an old laptop powersupply mounted on the bottom. At least I think it is a laptop powersupply - but why did I remove the plastic casing then? It might be a PSU from something else and I just patched on the small "phillips" mains connector to it. I don't really remember... And yes, those are Ikea tealight candle holders :-)
[attachment=2]
[attachment=1]
[attachment=0]
The first is really old - so old that I thought it was a good idea to have a dedicated TTL->RS232 converter mounted on it. The blob to the left contains a MAX232 and the capacitors for it.
[attachment=4]
[attachment=3]
The second has an old laptop powersupply mounted on the bottom. At least I think it is a laptop powersupply - but why did I remove the plastic casing then? It might be a PSU from something else and I just patched on the small "phillips" mains connector to it. I don't really remember... And yes, those are Ikea tealight candle holders :-)
[attachment=2]
[attachment=1]
[attachment=0]
Title: Re: What homemade test gear have you built and still use?
Post by: bearmos on October 05, 2012, 09:16:21 am
Post by: bearmos on October 05, 2012, 09:16:21 am
[quote author="matseng"]
The first is really old - so old that I thought it was a good idea to have a dedicated TTL->RS232 converter mounted on it. The blob to the left contains a MAX232 and the capacitors for it.[/quote]
haha, nice. I've got a "breadboard module" for the TTL-RS232 conversion ass well:) I never thought to hard mount it to the breadboard though (not a bad idea) - I wound up putting a right angle female header on it with extra long tails, so it could interface to a male header on the target PCB, or go into the breadboard.
I was sure I wasn't the only one to scab in a permanent power supply to my breadboard:) I think these are also commercially available, but obscenely expensive.
The first is really old - so old that I thought it was a good idea to have a dedicated TTL->RS232 converter mounted on it. The blob to the left contains a MAX232 and the capacitors for it.[/quote]
haha, nice. I've got a "breadboard module" for the TTL-RS232 conversion ass well:) I never thought to hard mount it to the breadboard though (not a bad idea) - I wound up putting a right angle female header on it with extra long tails, so it could interface to a male header on the target PCB, or go into the breadboard.
I was sure I wasn't the only one to scab in a permanent power supply to my breadboard:) I think these are also commercially available, but obscenely expensive.
Title: Re: What homemade test gear have you built and still use?
Post by: sqkybeaver on October 05, 2012, 01:49:27 pm
Post by: sqkybeaver on October 05, 2012, 01:49:27 pm
I'm still building home-brew test equipment
Title: Re: What homemade test gear have you built and still use?
Post by: Tuomas on October 06, 2012, 03:27:49 pm
Post by: Tuomas on October 06, 2012, 03:27:49 pm
Still quite new to this, and don't have a lot of income so building my own equipment is often a good option.
I used to have a self-made power supply, but that was replaced by a "real" lab supply, with current limiting.
I made a USB function generator over the summer:
[attachment=0]
Still sort of work in progress. No variable amplitude. Can't change the offset. But it's come in handy quite a few times already.
(More info on my website) (http://http://tuomasnylund.fi/drupal6/content/ad9833-based-usb-function-generator).
I used to have a self-made power supply, but that was replaced by a "real" lab supply, with current limiting.
I made a USB function generator over the summer:
[attachment=0]
Still sort of work in progress. No variable amplitude. Can't change the offset. But it's come in handy quite a few times already.
(More info on my website) (http://http://tuomasnylund.fi/drupal6/content/ad9833-based-usb-function-generator).
Title: Re: What homemade test gear have you built and still use?
Post by: sqkybeaver on October 06, 2012, 03:51:27 pm
Post by: sqkybeaver on October 06, 2012, 03:51:27 pm
[quote author="Tuomas"]I used to have a self-made power supply, but that was replaced by a "real" lab supply, with current limiting.
[/quote]
sounds familiar, a trip to the local surplus store with a few Jackson's usually gets one or two used pieces that need minimal work if any.
[/quote]
sounds familiar, a trip to the local surplus store with a few Jackson's usually gets one or two used pieces that need minimal work if any.
Title: Re: What homemade test gear have you built and still use?
Post by: fcobcn on October 07, 2012, 09:24:33 pm
Post by: fcobcn on October 07, 2012, 09:24:33 pm
I really enjoy building test gear and small electronic tools,
Here are some of them already published in the forum.
-The AVR transistor tester: viewtopic.php?f=19&t=3260&start=15#p32204 (http://dangerousprototypes.com/forum/viewtopic.php?f=19&t=3260&start=15#p32204)
-Pickit2: viewtopic.php?f=19&t=2848#p28084 (http://dangerousprototypes.com/forum/viewtopic.php?f=19&t=2848#p28084)
-LC Meter: viewtopic.php?f=19&t=3260&start=120#p32725 (http://dangerousprototypes.com/forum/viewtopic.php?f=19&t=3260&start=120#p32725)
-Superprobe: viewtopic.php?f=56&t=2751#p27032 (http://dangerousprototypes.com/forum/viewtopic.php?f=56&t=2751#p27032)
ATM I'm working on a ESR meter, based on this design: http://kripton2035.free.fr/digital%20es ... ssian.html (http://kripton2035.free.fr/digital%20esr/esr-go-russian.html)
, currently I have laid out the schematic and started to route the pcb.
Here are some of them already published in the forum.
-The AVR transistor tester: viewtopic.php?f=19&t=3260&start=15#p32204 (http://dangerousprototypes.com/forum/viewtopic.php?f=19&t=3260&start=15#p32204)
-Pickit2: viewtopic.php?f=19&t=2848#p28084 (http://dangerousprototypes.com/forum/viewtopic.php?f=19&t=2848#p28084)
-LC Meter: viewtopic.php?f=19&t=3260&start=120#p32725 (http://dangerousprototypes.com/forum/viewtopic.php?f=19&t=3260&start=120#p32725)
-Superprobe: viewtopic.php?f=56&t=2751#p27032 (http://dangerousprototypes.com/forum/viewtopic.php?f=56&t=2751#p27032)
ATM I'm working on a ESR meter, based on this design: http://kripton2035.free.fr/digital%20es ... ssian.html (http://kripton2035.free.fr/digital%20esr/esr-go-russian.html)
, currently I have laid out the schematic and started to route the pcb.
Title: Re: What homemade test gear have you built and still use?
Post by: sa5bke on October 09, 2012, 02:19:56 pm
Post by: sa5bke on October 09, 2012, 02:19:56 pm
[quote author="Tuomas"]I made a USB function generator over the summer[/quote]
I might, when I get time, try to replicate this. But I wonder, why is the upper limit ~3MHz in your build? I thought it was 12.5 MHz on the AD9833.
Eric
I might, when I get time, try to replicate this. But I wonder, why is the upper limit ~3MHz in your build? I thought it was 12.5 MHz on the AD9833.
Eric
Title: Re: What homemade test gear have you built and still use?
Post by: Tuomas on October 12, 2012, 10:27:30 am
Post by: Tuomas on October 12, 2012, 10:27:30 am
[quote author="sa5bke"][quote author="Tuomas"]I made a USB function generator over the summer[/quote]
I might, when I get time, try to replicate this. But I wonder, why is the upper limit ~3MHz in your build? I thought it was 12.5 MHz on the AD9833.
Eric[/quote]
The AD9833 can go all the way to 12.5MHz, but the sine wave gets very distorted above 3MHz. Something they don't mention in their datasheet... If you added some aggressive lowpassfiltering with a cutoff somewhere around 5-12MHz, you could probably get a decent sine wave up to that point. I just added a RC lowpass at ~3MHz. The sine wave is good enough up to that point.
Another annoying thing with the chip is that the amplitude of the sine and triangle is 0.6v, but the amplitude of the square wave is 3.3v (if I recall correctly) out of the chip. I used an opamp to amplify the signal. Sine and triange get amplified, square is clipped by the opamp. That's how they both end up with about the same amplitudes. Ugly...
I might, when I get time, try to replicate this. But I wonder, why is the upper limit ~3MHz in your build? I thought it was 12.5 MHz on the AD9833.
Eric[/quote]
The AD9833 can go all the way to 12.5MHz, but the sine wave gets very distorted above 3MHz. Something they don't mention in their datasheet... If you added some aggressive lowpassfiltering with a cutoff somewhere around 5-12MHz, you could probably get a decent sine wave up to that point. I just added a RC lowpass at ~3MHz. The sine wave is good enough up to that point.
Another annoying thing with the chip is that the amplitude of the sine and triangle is 0.6v, but the amplitude of the square wave is 3.3v (if I recall correctly) out of the chip. I used an opamp to amplify the signal. Sine and triange get amplified, square is clipped by the opamp. That's how they both end up with about the same amplitudes. Ugly...