Any EEs in the house? - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Lounge For casual talk about things unrelated to General Motors. In other words, off-topic stuff. And anything else that does not fit Section Description.

Reply
 
 
 
Thread Tools Search this Thread
Old 12-04-2006, 11:00 PM   #1
Senior Member
True Car Nut
Thread Starter
 
Join Date: Nov 2002
Location: Texarkana, Texas
Posts: 6,041
Thanks: 0
Thanked 0 Times in 0 Posts
Damemorder is on a distinguished road
Default Any EEs in the house?

So... I want to be able to "turn down" the speed of my electric R/C truck. I know PWM is usually used to do this, But I think I found a circuit that can be retrofitted. I found a variable speed fan in an old PC I was given, and with a 5K pot I can adjust between 0-1K to get the full range of motor speed.

Now here'* what I'm wondering, The circuit uses a LB1861 which seems to be good for 1.5A, I know the motor I want to control has to be over that, Can I use a transistor or MOSFET to 'up' the amperage and make the circuit work?


The datasheet on the LB1861:
http://www.ortodoxism.ro/datasheets/sanyo/ds_pdf
Damemorder is offline   Reply With Quote
Old 12-05-2006, 05:07 AM   #2
Senior Member
Posts like a Camaro
 
Join Date: Jan 2006
Location: Riverside, CA
Posts: 1,137
Thanks: 0
Thanked 0 Times in 0 Posts
chr0mius is on a distinguished road
Default

I like sausage.
chr0mius is offline   Reply With Quote
Old 12-05-2006, 05:16 AM   #3
Senior Member
True Car Nut
Thread Starter
 
Join Date: Nov 2002
Location: Texarkana, Texas
Posts: 6,041
Thanks: 0
Thanked 0 Times in 0 Posts
Damemorder is on a distinguished road
Default

LOL, I was wondering when this was going to get a reply...

I got ahold of a guy in my SCCA club who came over and showed me how to do it with an NPN a PNP and two MOSFETs. It wastes some of my mAh, but it works.
Damemorder is offline   Reply With Quote
Old 12-05-2006, 07:40 AM   #4
DINOSAURUS BOOSTUS

Expert Gearhead
 
BillBoost37's Avatar
 
Join Date: Mar 2005
Location: Enfield, CT
Posts: 41,391
Thanks: 0
Thanked 0 Times in 0 Posts
BillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of light
Default

How did you do this Dame..

Depending the transistors NPN and PNP you would have needed to supply their required voltage/ground to trigger them right?
BillBoost37 is offline   Reply With Quote
Old 12-05-2006, 08:38 AM   #5
Senior Member
Certified Car Nut
 
Join Date: Jul 2003
Location: Robbinsdale, MN
Posts: 15,408
Thanks: 0
Thanked 0 Times in 0 Posts
MOS95B is on a distinguished road
Default

So, um, why didn't you just get a smaller motor for the truck? or is it one of them cheapies you can't change parts in?
MOS95B is offline   Reply With Quote
Old 12-05-2006, 08:40 AM   #6
Senior Member
True Car Nut
Thread Starter
 
Join Date: Nov 2002
Location: Texarkana, Texas
Posts: 6,041
Thanks: 0
Thanked 0 Times in 0 Posts
Damemorder is on a distinguished road
Default

supply voltage powers the MOSFETs and transistors, the LB1861 triggers the transistors, which trigger the MOSFETs.

Like half of this since I only use one direction.
http://www.bobblick.com/techref/proj...e/hbridge.html
Damemorder is offline   Reply With Quote
Old 12-05-2006, 08:43 AM   #7
Senior Member
True Car Nut
Thread Starter
 
Join Date: Nov 2002
Location: Texarkana, Texas
Posts: 6,041
Thanks: 0
Thanked 0 Times in 0 Posts
Damemorder is on a distinguished road
Default

Quote:
Originally Posted by MOS95B
So, um, why didn't you just get a smaller motor for the truck? or is it one of them cheapies you can't change parts in?
It'* a Nikko Silencer. I think is was $20 in 1997. I'm not gonna buy a truck until I can make this work
Damemorder is offline   Reply With Quote
Old 12-05-2006, 08:47 AM   #8
Senior Member
Certified Car Nut
 
Join Date: Jul 2003
Location: Robbinsdale, MN
Posts: 15,408
Thanks: 0
Thanked 0 Times in 0 Posts
MOS95B is on a distinguished road
Default

Quote:
Originally Posted by Damemorder
Quote:
Originally Posted by MOS95B
So, um, why didn't you just get a smaller motor for the truck? or is it one of them cheapies you can't change parts in?
It'* a Nikko Silencer. I think is was $20 in 1997. I'm not gonna buy a truck until I can make this work
So, you can't just change out the parts... I had an RC10 way back when, and was an alternate driver for the "Tattooed White Trash" RC Monster Truck racing team here. So when I think RC, I think the "big boys"....
MOS95B is offline   Reply With Quote
Old 12-05-2006, 08:51 AM   #9
Senior Member
True Car Nut
Thread Starter
 
Join Date: Nov 2002
Location: Texarkana, Texas
Posts: 6,041
Thanks: 0
Thanked 0 Times in 0 Posts
Damemorder is on a distinguished road
Default

I would be using more VCR parts If I hadn't found this thing in the trash, Makes some of it easier.

I'm into scale rock crawling anyway, so even if I had the cash to have a truck, It wouldn't be useful.
Damemorder is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Any Graphic Designers in the House? redwingsfan34 Lounge 1 05-15-2007 10:13 PM
Any guitarists in the house? ForeverSilent004 Lounge 14 02-13-2007 05:48 PM
My house fuse breaker keeps tripping Any Electricians here? Shadow Lounge 38 05-16-2006 04:38 PM
Any body know of any good web-sites? vze3r85p Lounge 6 10-23-2003 06:21 PM
Any stock SSEi owners have any 'dealings' w/Chrysler 300M's? GTP2SSEi General GM Chat 12 07-26-2003 12:48 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 05:09 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.