New ways of doing things
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Posts: 46,084
>Just my two cents on this issue I played around with transistors for
>a little while and finnally figured it out but I've never been very
>fond of the singly packaged transistors. I suggest if your just
>interseted in having it work (instead of the workings of electronics)
>a Transistor Array in IC form is much easier. I'm quite fond of the
I have been trying to come up to speed on the latest electronics after a
long absence and have been investigating MOSFETs. I suggest that newbees
who are interested in learning electronics investigate MOSFETs too. For
example, the ZVN4206AV is designed to operate relays up to 600ma coil
current directly from your Stamp without any additional resistors or diodes.
Moreover, these transistors are smaller than your normal TO-92 cases. See
AN10 at http://www.zetex.com/3.0/3-8-1a.asp
Some MOSFETs have such a low forward voltage drop that they are essentially
relays. For example, the IRL3803 has a resistance of only 0.009 ohms @ 4.5V.
This transistor comes in a TO-220 case and can switch 120 amps!!! I don't
think any additional components would be needed to operate an inductive load
as large as a automobile starter motor from your Stamp. See
http://www.irf.com/technical-info/an937/an-937p5.htm
I have been using the N channel MOSFETs like PNP bipolar transistors to
switch the low side of circuits. When you want to sleep and save power for
a while you can simply switch-off the ground return for all chips you aren't
using. (I don't know if this is good engineering but it seems to work OK so
far... Anyone have comments??)
Newbees also need to be aware of "Schottky" diodes. Schottky diodes have a
lower voltage drop than standard diodes. This is important when one need's
to minimize voltage drop through the diode (e.g., solar apps). The SB540 is
a nice one
http://www.digikey.com/scripts/us/dksus.dll?Detail?Ref=60049&Row=188331 40V
& 5A. I measured a 0.21 forward voltage drop (a 1n4001 drops about 0.67V).
Lot's of neat goodies out there! Lot's of new ways to do things.
Jay
>a little while and finnally figured it out but I've never been very
>fond of the singly packaged transistors. I suggest if your just
>interseted in having it work (instead of the workings of electronics)
>a Transistor Array in IC form is much easier. I'm quite fond of the
I have been trying to come up to speed on the latest electronics after a
long absence and have been investigating MOSFETs. I suggest that newbees
who are interested in learning electronics investigate MOSFETs too. For
example, the ZVN4206AV is designed to operate relays up to 600ma coil
current directly from your Stamp without any additional resistors or diodes.
Moreover, these transistors are smaller than your normal TO-92 cases. See
AN10 at http://www.zetex.com/3.0/3-8-1a.asp
Some MOSFETs have such a low forward voltage drop that they are essentially
relays. For example, the IRL3803 has a resistance of only 0.009 ohms @ 4.5V.
This transistor comes in a TO-220 case and can switch 120 amps!!! I don't
think any additional components would be needed to operate an inductive load
as large as a automobile starter motor from your Stamp. See
http://www.irf.com/technical-info/an937/an-937p5.htm
I have been using the N channel MOSFETs like PNP bipolar transistors to
switch the low side of circuits. When you want to sleep and save power for
a while you can simply switch-off the ground return for all chips you aren't
using. (I don't know if this is good engineering but it seems to work OK so
far... Anyone have comments??)
Newbees also need to be aware of "Schottky" diodes. Schottky diodes have a
lower voltage drop than standard diodes. This is important when one need's
to minimize voltage drop through the diode (e.g., solar apps). The SB540 is
a nice one
http://www.digikey.com/scripts/us/dksus.dll?Detail?Ref=60049&Row=188331 40V
& 5A. I measured a 0.21 forward voltage drop (a 1n4001 drops about 0.67V).
Lot's of neat goodies out there! Lot's of new ways to do things.
Jay