A következő címkéjű bejegyzések mutatása: PCB. Összes bejegyzés megjelenítése
A következő címkéjű bejegyzések mutatása: PCB. Összes bejegyzés megjelenítése

2023. május 22., hétfő

Analog Multimeter 3. - PCBWay Review

My boards arrived Yesterday from PCBWay.

As this is the first time I use them as board house I'd like to write a small review here.

I'm ordering PCBs from various manufacturers in the last 14 years. I started with some local manufactures. Those guys had horrible prices and not so good quality (anything above the single side board had additional cost, etc.)

10 years ago I changed to the board houses located in China. As my projects mostly has no time constraints, the long delivery time hadn't be an issue to me.

There were a certain PCB size what manufactured on the low cost ($5 + shipping). This started with 50x50mm, then become 70x70 and lately 100x100. Almost all of the manufacturers today provide 10pcs 100x100mm two sided, masked, silkscreen printed boards for 5$ + shipping.

This is where we stand today.

Lets check the order process of PCBWay. I had a simple 100x50mm board, for prototyping my SuperTracking regulator (based on Walt Jung/Jan Didden design).

It is a great thing to have a gerber viewer and automatic size calculator in your order process. Here the PCBWay site tricked me a bit. I didn't find this feature on the first sight. It is not reside on the main ordering page you see at first. You need to switch to the "Quick-order PCB" page to get this.

I absolutely love this feature:

It means you order your PCB with HASL (tinned) finish and if you are lucky you get ENIG (gold plated) finish. To understand, the manufacturers put your hobby projects into the big orders process. If you tick this checkbox, you may get a gold finish. The manufacturer on the other side has greater flexibility where they put your order. This is an absolutely win-win situation.

We care about the environment. The EU doesn't allow lead based solders for a while in the consumer electronics devices. At the board houses, you can select between the leaded and the lead free finish. The manufacturers I seen previously charge extra for the lead free finish. This come from PCBWay with no additional cost.

If you ordered already PCBs, you always find a tiny order number on your board somewhere. In most of the cases this doesn't cause any problems. You have the paying option to remove this number. This is not always necessary. Check my previous design, what is the scale of the meter under design. There could be a problem to see this number on the visible area of the board. Here you can add special request written where you want to place this number. At other sites I seen a method, you can add a specially formatted text to your silkscreen where the manufacturer can put this number. I feel this point as room for improvement.

At PCBWay you pay your order after the review (in few hours - it took me a day, probably because I ordered my board during the weekend). Other manufacturers require the payment upfront. I think it is matter of taste. I prefer this method. It give me some time to review myself if everything is ok, I didn't make a mistake at the order (unfortunately paying upfront caused me trouble in the past).

One additional thing about the order process. Providing and stating to provide IOSS (Import One-Stop Shop) is a help for the EU customers from two point: the order arrive faster and you don't need to do the paperwork at the local customs or tax authorities.

The order of mine arrived on Monday.

The quality of the boards are excellent. Didn't find any issue with it. This is the quality I expect from the boards I want to use.

I was eager to populate it as soon it arrived. I was sure that all of the required components arrived. Jumped into the build. Immediately realized that three parts are missing.

One is the voltage reference I intend to use. It is my fault, forget to order it.

The other two is the dual OpAmp and the small NPN transistor. I got a message from Mouser: "Shipments of this product must be direct to an END CUSTOMER from an AUTHORIZED DISTRIBUTOR only.  Your customer must order this product directly from Mouser or another authorized distributor."
Come on! I never sold components as a reseller. I'm just an engineer who time-to-time fix things, design equipment.

Contacted Mouser, It took around three days to settle this.

So yesterday finally ordered the remaining components. Waiting for the arrival.

2017. november 14., kedd

High Voltage DC Power Supply 2.

!!!DANGER!!!
The circuit described bellow is dangerous. Using it improperly will kill you. On the other side I may also made mistakes during the design and built. I'll take absolutely no responsibility for it. If you want to build it, please don't ask for circuit board or help. I won't help you.

As the other PCBs are arrived for the supply, I continued the build.
Finished the separated isolated supplies for the panel meters (these are nothing else just a simple dual 7809 based linear supplies):


Also added the power distributor and some wiring for the backpanel:


Connected the panel meters and, milled parts of the front panel (manually as my CNC mill is still broken)
How the whole thing looks like today:


And its working, partially:


As you see the decimal dot is on the bad place (it is more likely 330V than 33V)
In addition I took a picture of the board on thermal camera. You can clearly see that the two capacitor draining resistors getting warm:



So I can tell, it is progressing, but quite few things still ahead of me:
  • Mill a hole for the mains socket and the circuit breaker to the backpanel
  • Mill the holes for the banana jacks to the front panel
  • Finish the wiring
  • Set the correct decimal dots
  • build a dummy load to be able to test the current measurement
  • Calibrate
  • Paint the front panel
  • Build the phase switching electronics (not mandatory, maybe after finish)
  • Create the console for the caps


continue...

2017. november 11., szombat

PCB manufacturing

Quite a few of my new designs are ready. Arrived during the last week.
Just find time to build, test and write about them: