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DC motor driver circuit: do I have this right?
Nice Work! I'm happy to see you managed to do the job! Even if there are 12 trans in this dual H-bridge driver and it probably costs more than an IC equiv, I'm sure you learned a...
Monday, 21 April 2008 - 22:02
Detecting RS485 idle
Polling is perfectly fast for 100+ nodes on a bu as well! You can buy very nice RS-485 drivers (I use some from Linear Technology) which can send/receive in the Mbaud range and...
Saturday, 29 March 2008 - 01:12
Quoth the Raven!
Another Ravens landed! Right now to me! They are all OK, no problem with the speakers or anything else. Now it's time to play! Thanks a lot ATMEL and Magnus! I think this was the...
Wednesday, 26 March 2008 - 23:10
3 terminal 5v regulator, current flowing backwards.
Put a Schottky before the input of the regulator! Easiest way. Peter
Friday, 21 March 2008 - 17:25
DC motor driver circuit: do I have this right?
Hi barney_1! You posted a better schematic than I did :-)! The diode should be connected through the motor connection and not the transistor. It is to short the spikes coming from...
Wednesday, 19 March 2008 - 10:37
DC motor driver circuit: do I have this right?
peret wrote:Quote:To switch off the transistor put the pin in HighZ mode. This will not work if the PNP supply is more than a volt higher than Vcc, because all AVR IO pins have a...
Wednesday, 19 March 2008 - 00:41
DC motor driver circuit: do I have this right?
Quote: I have a couple pnp transistors on hand but the avr can't provide enough voltage to turn them off. You will never be able to switch off a PNP with a microcontroller's pin...
Tuesday, 18 March 2008 - 21:13
DC motor driver circuit: do I have this right?
NPN transistor is not for the high side! The NPN transistor needs ~0.65 V between the emitter and base to switch on. So if you use your AVR from 5V supply, you output ~5V on a pin...
Tuesday, 18 March 2008 - 17:31
DC motor driver circuit: do I have this right?
Quote:Hei, you still can use PNP even it is controlled with 5 volt! I've done this. The trick is using pull up resistor. Connect pin 1 of resistor to base of transistor and to uC...
Tuesday, 18 March 2008 - 10:41
DC motor driver circuit: do I have this right?
Torby wrote:You don't have to be afraid of a PNP. It's just the polarity opposite of an NPN. If you want the motor on when you pull the base low, your PNP will do fine, as long as...
Monday, 17 March 2008 - 22:11
DC motor driver circuit: do I have this right?
No! Collector has a fixed saturation current. That is the value where any more growth in the base current make no current growth in the collector. But if your collector current is...
Monday, 17 March 2008 - 16:43
DC motor driver circuit: do I have this right?
It is a very short datasheet! There are datasheets from other manufacturers also: http://www.datasheetcatalog.net/datasheets_pdf/P/N/2/2/PN2222.shtml You can look at to the ON...
Monday, 17 March 2008 - 14:54

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