Custom part design "Rimu PCB"

[Richard Hjemmen]

Newbie alert!! [img]tongue.gif[/img]

Hi,

I have just purchased RIMU PCB and I am about to start to draw a Purple Audio-style 1176.

The footprint-library in RIMU is not very big and I guess I have to draw custom parts for my project. My question is:

The libray contains a few footprints named TO-"number". Is, for example, TO-92 a standard footprint that would fit any "TO-92 component" or does that TO-thing define something else?

Thanks

Richard

[Mark Burnley]

Hi Richard,

All semiconductors have a code number for the case. A 2N3055 for example is a "TO-3" case. A BC109 is a TO-18. 2N3094 etc. are TO-92. But watch out!...TO-92 comes in a wide variety of suffixes- TO-92a, TO-92b etc. This means that the component has the same physical "footprint", but the electrical pinout to the device is different. The best thing to do is Google the part # you are looking for followed by "pdf". This will hunt down the datasheets for the device. Check out the pinout (usually on the first page) and a handy table should make you aware of any different pinouts.

In a PCB package, when you define a device package, the software will just place a "TO-92" pad. If you're drawing it by hand, it's then up to you to work out the pinout!

But, if you have schematic>PCB software, you will have to define the actual device number including suffix, so the autorouter knows how to connect the package.

BTW, are you designing a 1176 board from scratch? Have you re-designed the actual circuitry? It just seems a rather large project to begin PCB layout on

Good luck with it!

[img]graemlins/up.gif[/img]

Mark

[Richard Hjemmen]

Thanks Mark,


I have UTC O-12's and UA-5002's and from what I have learned here I should go with the Purple-design instead of the Gyraf.

Thanks again.

Richard

[ January 25, 2004, 07:01 AM: Message edited by: Richard Hjemmen ]

[buttachunk]

what are the differences ?

[Richard Hjemmen]

Originally posted by buttachunk:
what are the differences ?

..something about the Purple output being class A and the Gyraf not. I might be wrong here.

Mark, one of the transistors in the Purple is 2N5088. The ON-semiconductor datasheet tells me it's a TO-92 (TO-226AA), pin1=emitter pin2=base and pin3=collector. The Rimu-software have TO-92 and also a TO-226AE in the library but no TO-226AA.


Richard

[Mark Burnley]

Hmm,

If you're making it by hand, just lay it out as-per-datasheet. If it's autoroute, just design a basic circuit with the transistor driving an LED with an input in Common Emitter mode, and see what the software does!

[img]smile.gif[/img]

Mark

[Richard Hjemmen]

My goal is to get the gerbers, then I'll have someone make the PCB's. I try to focuse on pin-space and holesizes for now.

Richard

[Flatpicker]

Hi, Richard. I just bought the Rimu "standard" package a few weeks ago. You'll probably have to make a lot of parts for stuff like we're doing. At least I've had to, anyway. I haven't used the Rimu very much yet but I'm starting to get the hang of it.