BWD 603B Mini Lab  - Page 1
Forum section: electronics / general

author: aparlett
author_rank: Regular Contributor
timestamp: November 15, 2011, 09:11:23 am
content: hello guysIm looking into BWD 603B Mini Lab, From what I see it looks like an awesome addition to a home lab.what do guys think about it? and what is a reasonable price to pay.On another note I noticed it was made in Melbourne, what ever happened to the company its sad that they are not around anymore.thanks antony

author: saturation
author_rank: Super Contributor
timestamp: November 15, 2011, 10:49:08 am
content: From the description, its obsolete and fairly expensive for a used item. You can do better spec wise buying each piece individually: function generator, power supply, both ac and dc and build your op amp when you need it.http://www.ebay.com.au/itm/BWD-603B-Mini-Lab-Oscillator-Power-supplies-OP-Amps-training-and-hobby-aid-/180750737517?pt=AU_B_I_Electrical_Test_Equipment&hash=item2a1595606d

author: EEVblog
author_rank: Unknown
timestamp: November 15, 2011, 10:57:44 am
content: These were good value on the 2nd hand market 15 years ago, maybe even 10 year ago, but now are ancient. Better value to be had elsewhere.Many old timers with fond memories of them being used in their school labs keep the prices high for such old bits of kit.Dave.

author: aparlett
author_rank: Regular Contributor
timestamp: November 15, 2011, 10:59:48 am
content: would you be able to recommended any goodac-power supply+/- dc power supplythanks antony

author: aparlett
author_rank: Regular Contributor
timestamp: November 15, 2011, 11:01:56 am
content: I'm getting a function gen with my scope so I have that covered.just dc/ac power is still on my list

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: November 15, 2011, 12:09:02 pm
content: Amazing some ask as high as almost 600 EUR for it on ebay. Definately obsolte equipmentFor power supply look Atten i like their all, there is Hameg too (pricey) but they never let me down

author: amspire
author_rank: Super Contributor
timestamp: November 15, 2011, 12:48:36 pm
content: The BWD mini Lab is actually not a bad thing to have at all. Nothing in it is spectacular, but it provides a lot in one place. 0 to 200V DC, +/15V power supply, the function generator, and the power opamp was actually unique and very handy.But the prices have gone nuts. Under $100 it is an interesting proposition, but at $400 - no way.BWD was a company of really great designers. They managed to design a lot of very impressive equipment from a small, low budget operation. The Mini Lab may be fairly basic, but it will be well designed, and it will work well. BWD was principally in the oscilloscope design business, but they also made some good power supplies. The Mini Lab was a one-off idea, but it seemed to be popular.Their best product was the Powerscope range. If you were working with motors, 3-phase or switching power supply design, these were just amazing. 4 fully differential channels so you could clip the channel probes between any two point you liked. Rated at up to 660VAC input on any channel. Didn't matter if the points were grounded, floating. Most important of all, the differential inputs really worked.Richard

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: November 15, 2011, 01:28:04 pm
content: Does somebody have schematics of it? Im curious what is insideEdit, i found it but cant attach it here because of size.

author: amspire
author_rank: Super Contributor
timestamp: November 15, 2011, 02:21:24 pm
content: Quote from: hacklordsniper on November 15, 2011, 01:28:04 pmIf anyone wants to look at the manual, you can download it from here:http://www.ebaman.com/index.php/remository/ELECTRONICS/Test-Equipment/BWD/BWD-603B-Mini-Lab-%28Issue-23%29/but you will have to register first.The power amp is interesting. It can do +/- 15V p-p output at up to 1A (current limited) and frequency to 80KHz.It has 3 switchable modes - as an amplifier, as a 5V DC fixed supply, or as a bipolar -15V to 15V power supply.In addition there is fixed +/- 15V supplies, and variable +/- 1 to +/- 15V supplies (LM317/LM337 regulators).The function generator doesn't use a function generator IC - it is all discretes and quite well designed. Even the triangular wave to sinewave shaper is custom designed and it gives 0.6% distortion which is not bad at all for this type of design.Also it looks like there was a later version that is still being sold - the 604:http://www.mcvan.com/images/stories/acrobat/bwd604v3.pdfThey have got rid of the 6.3V ac (for valve heaters) and the 200VDC power supply, but the low voltage supplies are beefed up, and it includes a 20MHz function generator and frequency counter. Also now has digital displays.Richard

author: aparlett
author_rank: Regular Contributor
timestamp: November 15, 2011, 11:44:36 pm
content: that doesn't look too bad I wonder how much it will cost.Mabby it might be better if I build my own supplies, I don't think it would be that hard.or just look else where any ideas?

author: amspire
author_rank: Super Contributor
timestamp: November 16, 2011, 12:13:02 am
content: Quote from: aparlett on November 15, 2011, 11:44:36 pmI am sure the price will not be competitive if you are comparing it to Chinese supplies and instruments. I have never actually seen the BWD 604 anywhere, but it would be ideal for places like Tech colleges. That is probably where they all go. Never seen one on ebay.When you start looking at new power supplies from companies like Agilent, the prices are often over $1000, and so if you are looking at the price of several power supplies, a function generator, a counter, a DMM, a bipolar supply that can sink and source (most power supplies cannot sink) and whatever else the 604 can do, it does not look bad from the point of view of a teaching college. All the outputs are protected, and if a student does blow one up, they are probably dead easy to repair. Other then the transformer, all the parts will probably be off the shelf parts.Richard.

author: Unknown
author_rank: Unknown
timestamp: November 16, 2011, 12:44:51 am
content: If they're designed for education, expect them to be way overpriced. Those integrated solutions tend to be either more expensive than discrete instruments, inferior, or both. The only advantage is size. I believe Velleman makes an integrated soldering station / power supply / multimeter that sucks at all three. One thing you lose, regardless of quality, is flexibility. You might want a DDS function generator for better fidelity. Or you might not care about that function generator at all but want a beefier power supply.The only thing special appears to be the amplifier, although that might just be an OPA541 with some feedback resistors and binding posts. Not commonly found in hobbyist equipment, but can't remember needing one too many times either.Apart from this, the specs of the current version are nothing special. Standard old-fashioned analog function generator. Four digit frequency counter. Power supply (possibly L200/LM723-based) without adjustable current limit. 3.5 digit DMM with 1% accuracy without auto ranging.

author: amspire
author_rank: Super Contributor
timestamp: November 16, 2011, 02:44:12 am
content: For educational uses, when you are looking at the specs, quite often less is better.Which one of us would like to do without a current limit control on a power supply? But imagine being the poor lab technician at a college who is continually asked to "fix" power supplies that don't output anything just because some clueless has turned the current control down to zero.1% accuracy is all you need for teaching. In fact is is a good idea to have to make students understand limits of accuracy and resolution. You don't want stuff that is 0.001% accurate except for people doing serious research.If the power supplies are really simple - such as using the LM317/LM337 as the BWD603B did, then imagine how simple it is fixing blown power supplies. Probably would take 10 minutes to diagnose and fix it. That sort of simplicity is priceless for a college. Also the biggest advantage of all is it is easy to secure a single fairly large box - no handheld DMM's to walk out the door.The BWD designers were capable of designing top performing hardware, so I am sure that the Mini Labs were built to the specs wanted by customers in the educational industry.Richard

author: Unknown
author_rank: Unknown
timestamp: November 16, 2011, 06:02:48 am
content: My comments were about the suitability for a home lab, not education.