Bob Parker's Blue ESR Meter Assembly & Comments

[zeus]

Re: Bob Parker's Blue ESR Meter Assembly & Comments

ROTFL!!! I think I found my long distance (Type A) twin. Looking at the pics,
I saw you did all the anal crap I did:

- Tolerance bands on resistors are all down and to the right.
- All transistors are straight as an arrow, and probably the same height.
- Caps are all facing in a way that you can read them.
- HERE's THE BIG ONE; going over to $hit Shack and buying dip sockets.

I love it!
The only thing I did different is cutting off the banana end and soldering small
alligator clips to the leads. I just couldn't see spending another $10 on cheap
test lead ends. My little mod works great, when I touch the clips together the
meter reads 0.03 before I zero it out.

BTW Krankshaft, your PCB board looks great. LOL!

Take care; brother from another mother.

[Krankshaft]

Well I finally broke down and purchased an ESR meter and thanks to the posts here the Blue meter was the right choice for me.

It's cool looking blue displays and low dropout regulator won me over.

Another thing that these kits finally have is a battery cover for the 9 volt battery. So replacement doesn't need tools. That alone was reason enough for me to buy this meter.

I have read a few posts about the Dick Smith meters screws getting worn out from battery replacement.

I had a couple of issues during assembly and no I'm not talking about solder bridges.

I will admit I was pretty tired during assembly and wasn't running on all fours if you know what I mean . But I think that these mistakes that held me up can happen to others.

I've decided to share my assembly experience so that others can get this meter up and running with less head scratching.

This is by no means the first time I've assembled a kit I have assembled many kits and they've all worked the first time.

Okay so let's get on with how the kit was shipped to me.

It came in a little white box from Anatek with foam wrapped around it for protection.

When unpacked this is what I had:

See attached picture 1:

Here is a picture of the unassembled PCB:

See attached picture 2:

Please note that the probe ends in the large bag above WERE NOT included. I had to buy them for $10.00 a set. I purchased both the alligator clips and the standard multimeter probes.

This is my first gripe about this kit there were NO probe ends included.

This really disappointed me especially since NO WHERE on the Anatek site did it say that you needed to buy them separately.

Not only that if you assembled the kit to realize this later you couldn't test the resistor to calibrate the meter (more on that later).

So make sure that you get yourself a set of them. You Dick Smith guys were better off and had probes included.

The next issue I had was there was no printed manual you can view the manual before purchasing on Anatek's site and they e-mail it to you after your purchase.

This was a disappointment but no real issue.

So all of those things aside lets get into kit assembly.

The first thing that striked me as odd is on the silk screened PCB there were no component designation numbers like I'm used to (R25, C12, etc). There were only part values (220R, 27K, etc).

While I'm sure that the intention of this was to make assembly easier it can also lead you astray. For example there are a couple of 1% resistors on the board with the same values as 5% resistors so in actuality you could place a 1% resistor where a 5% resistor was made to go and vice versa.

The easy way to make sure you don't slip up is to look at a picture of the board with the component designation numbers on it in the manual. Then flip a page forward to see a picture of the board with the component values on it and make sure that the number of the component matches up with the component value.

Personally I think it would have been alot easier with component designation numbers silk screened on the board.

Moving on the next problem I had was with the 2 variable POTs included with the kit one was labeled 102 and the other 103. Unfortunately in the manual they were only referred to as a 10K trim POT and a 220 ohm trim POT. Simply measuring with my DMM with the POT turned in one direction solved that easily.

But again a simple revision to the manual stating that 103 is 10K and 102 is 220 will prevent any POT mix up entirely.

The rest of the assembly went easily the caps on this meter (unlike the EVB Portuguese meter that used bad Lelon caps) were Nichicon with 1 Panasonic in the mix. So you're using good caps to find bad caps and not the other way around .

I decided to use some Panasonic FCs instead of the included caps and a Panasonic SU for the bipolar cap I placed a dab of hot glue under it so it stays firmly bent over. I also upgraded the SU Bipolar cap to 47uf from the stock 22uf the Dick Smith kits used 47uf and the Blue manual said that it was acceptable as well.

Another thing left out of this kit that was included in the Dick Smith kits was IC sockets for the shift register and the microcontroller.

While I don't hope to ever need to use them it's always a nice option to have in case the worst does happen.

So a trip to Ratshack and I picked up 1 18 Pin socket (for the microcontroller) and one 16 pin socket (for the shift register) for just over 2 bucks.

So I finish assembly and everything looks good so I decided for the heck of it to run the microcontroller diagnostics to check my assembly.

So I make sure that VR1 is set to the center then make sure that R30 is bridged (this bypasses the voltage regulator I believe) and hold the power on button and F2 flashes on the screen.

So I look up what it means and I chase ghosts for about an hour thinking I did something wrong. Until I decide to read the directions more carefully.

They say in a nutshell that you can't use a 9 volt battery for this test and that the input voltage must be between 6.2 and 6.8 volts.

Not having a truly variable bench supply I set my fixed variable supply with a rotary switch to 7.5 volts and ran the diagnosis again thankfully .8.8 appeared on the display which meant everything was fine.

This mess up was all me and of course wasn't anyone's fault but mine but it's a good thing to remember if you want to use this function.

The next step was to calibrate the meter for this purpose they included an 82 ohm 1% resistor calibration is easy simply zero out the probes and test the resistor then adjust VR2 until the meter reads 82.

Take your time on this and make sure that you zero out the probes well. To test your calibration shut the meter down and power it back up zero out the probes again and test the resistor it should still read 82 ohms.

Okay now let's get into the hazy part of the manual labeled "Battery Warning Setup".

The point of this circuit is to trigger a flashing b on the display and dim the display to conserve power when the output from the 9 volt battery drops to 5.5 volts (the regulators dropout voltage).

Of course as you've read above I don't have a truly variable bench supply and 5.5 volts isn't exactly a standard output voltage.

So I build the little voltage regulator circuit pictured in the manual.

Sadly the components for this circuit weren't included but can all be found at Ratshack. I happened to have the components in that huge mess which is my parts drawer.

See attached picture 3:

I used an NTE123AP that I had on hand which was a sub for a common NPN 2N3904.

It is VERY IMPORTANT that you adjust this circuit while the meter is running if no load is being placed on the battery the input voltage will be off.

I soldered the output leads from the regulator circuit to the PCB while leaving the included battery clip installed then I simply connected the battery to the little circuit.

I then placed my probes on the other battery clip so that I could measure the regulators output with one hand and adjust the regulators pot for 5.5 volts with the other.

Now onto the actual calibration I had my next issue when the meter was powered on the low battery indicator started flashing I then attempted to turn the adjusting POT clockwise and the indicator didn't go off. Turning the POT to both extremes didn't shut it off.

Puzzled I turn the POT fully clockwise and turned the meter off then on and the indicator turned off. I then turned the POT counter clockwise and the b indicator came on I then turned the POT clockwise again.

You would think that this will turn the indicator off.

However this is untrue the manual neglected to mention that the low battery indicator is a latching circuit in other words once it comes on the only way to shut the indicator down is to power the meter off then on.

This makes sense to design the circuit this way since it would prevent the indicator from flickering on and off if the battery was jumping back and fourth past the threshold voltage.

While this was again a misinterpretation on my part and the manual clearly stated turn the pot fully clockwise then turn it counter clockwise until the indicator comes on it not fully explaining why lead to some confusion.

The assembled kit board:

See attached picture 4:

The fully assembled kit:

See attached picture 5:

I also put on some clear feet so that it won't skid all over my bench and so I don't elbow it onto the cement floor .

See attached picture 6:

Overall after assembly this meter is every bit as good as the Dick Smith kits with some extras like the battery cover and the more efficient blue displays.

I am very pleased with this meter and it's a great option for those of you who haven't been able to grab the quickly vanishing Dick Smith kit.