Messages

881

General Mach Discussion / Re: Manual pulse encoder & mach3

« on: January 19, 2022, 01:46:18 AM »

Hi,
R1 nd R2 just provide some base resistance, say 1kOhm would be fine. T1 and T2 are indeed NPN transistors.
When the base of T1 is energised then T1 will saturate and pull the collector down to 0V , or very close to,
say 0.2V.

Thus the two transistors are just current controlled switches. The current in the base circuit is likely to be 100uA, while
the collector-emitter current will be several mA, ie the transistors provide amplification of a low current, either A or B outputs
and can switch several mAs.

Craig

882

General Mach Discussion / Re: Manual pulse encoder & mach3

« on: January 19, 2022, 01:16:23 AM »

Hi,
I think you will need a 12V supply, but it need only be very low current.

If you need to amplify/buffer the AB MPG outputs something very simple like attached pic.
The transistors need only be small signal types, say BC547's or similar...I have hundreds of them lying around, and as
most of my parts are now surface mount I very rarely use these through-hole types any more.

Craig

883

General Mach Discussion / Re: Manual pulse encoder & mach3

« on: January 19, 2022, 12:49:39 AM »

Hi,
the C10 shows a 4.7kOhm pull-up/pull-down resistor, so the input impedance will be around 4.2kOhm.
You'll just have to try the AB outputs of the MPG, they may be enough to trigger the BoB, but then again maybe not.
My recollection when designing/building my pendant was that to output impedance of the AB outputs was 10kOhm.

Craig

884

General Mach Discussion / Re: Manual pulse encoder & mach3

« on: January 19, 2022, 12:07:05 AM »

Hi,
what it means is the outputs of the MPG are fairly weak and you may require some buffering between the outputs and your BoB
inputs. In my case I just used a single NPN transistor, 2 cents each variety....

Craig

885

General Mach Discussion / Re: Manual pulse encoder & mach3

« on: January 18, 2022, 11:58:52 PM »

Hi,
my new mill has Delta servos and has 24VDC signaling. I wired 24V to the pendant, and have a LM8712 regulator to drop the 24VDC down to
12VDC for the MPG. The MPG outputs both source and sink current, but not much, they have an output impedance of around 10kOhm.
I run the outputs into the bases of two NPN transistors so that the collectors could sink 24V and signal my BoB. To pull the BoB low requires
5mA, an the AB outputs of the MPG cannot do that directly.

Craig

886

General Mach Discussion / Re: Manual pulse encoder & mach3

« on: January 18, 2022, 08:44:10 PM »

Hi,

The MPG is a nonessential option so you can take a chance on the cheap route, especially if this is for hobby use. If it dies you can get along with the regular jog until you find a better one.

I use my machine multiple times a day, and not having a reliable pendant is a PITA, not a show stopper but bloody inconvenient....and that's why I went to the effort to
make my own.....its as reliable as I design it to be......with the only real unkown being the MPG itself, and for that purpose Japanese quality just can't be beat.

Craig

887

General Mach Discussion / Re: Manual pulse encoder & mach3

« on: January 18, 2022, 08:40:01 PM »

Hi,
I use a service that is run by the New Zealand Postal service. They maintain a warehouse in Portland, Oregon. As a participating customer I have any US items shipped to
Oregon, usually $15-$20USD, and then the service kicks in, they tell me how its going to cost to get to New Zealand and also the New Zealand Good and Services Tax (15%),
I pay them and it turns up on my doorstep about 10 days later. Too easy!

For example the MPG I bought was $26USD, plus 14$USD shipping to Oregon or $60NZD. I paid NZ Post $39NZD for shipping to New Zealand and the tax. Not cheap, but not really expensive either,
and certainly very convenient.

Craig

888

General Mach Discussion / Re: Manual pulse encoder & mach3

« on: January 18, 2022, 08:02:49 PM »

Hi,
yeah, looks good....but does it smell of Chop Suey??? Whats the bet it's Chinese.

This is another Japanese brand...not cheap and second hand, and yet STILL preferable to Chinese rubbish:

https://www.ebay.com/itm/131432378954?hash=item1e99faf24a:g:YqEAAOSwBLlU41Sn

5V input, A ans B outputs.

Craig

889

General Mach Discussion / Re: Manual pulse encoder & mach3

« on: January 18, 2022, 07:51:12 PM »

Hi,

The one Craig listed is 12V not 5V, which means I'd also need to buy a power source on top of the MPGs

Very true, but its Japanese quality, and that's quality with a capital Q. Sensei have a range of different models, 12V, certainly....after all I have one, 24V I recall seeing and I think
a +5V/-5V one as well.

Craig

890

Mach4 General Discussion / Re: Help with C# DLL usage development

« on: January 18, 2022, 05:37:51 PM »

Hi,
what is it that your trying to do? Mach4 has a perfectly good scripting language/environment in Lua.....so why use C#?

Craig