OCCRA
Go to Post It's one thing to post thoughts, guesses, opinions - that's all good ... However, it's [different] to make statements claiming first hand knowledge & facts without actually having first hand knowledge, facts, or accurate information. - Jason Morrella [more]
Home
Go Back   Chief Delphi > Technical > Robotics Education and Curriculum
CD-Events   CD-Media   CD-Spy   FRC-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Closed Thread
Thread Tools Rate Thread Display Modes
  #1   Spotlight this post!  
Unread 03-01-2003, 12:38 PM
Gui Cavalcanti's Avatar
Gui Cavalcanti Gui Cavalcanti is offline
Robogeek
no team
Team Role: College Student
 
Join Date: May 2001
Rookie Year: 2001
Location: Needham, MA
Posts: 224
Gui Cavalcanti is a name known to allGui Cavalcanti is a name known to allGui Cavalcanti is a name known to allGui Cavalcanti is a name known to allGui Cavalcanti is a name known to allGui Cavalcanti is a name known to all
Send a message via AIM to Gui Cavalcanti
Optical sensors with EduBot

Is there any good way to power a banner sensor/optical sensor with the EduBot? We could connect it in the same way that we would for the RC, but we are worried about whether the ground pin on the EDU-Rc could accept the 7.2 volts from the battery, instead of the 5 volts sent by the signal pin. The banner sensors work on 7.2 volts, but they do not work on 5 (6.6 is about the limit).
__________________
Gui Cavalcanti

All-Purpose College Mentor with a Mechanical Specialty

Franklin W. Olin College of Engineering, Class of 2008
  #2   Spotlight this post!  
Unread 03-01-2003, 02:22 PM
Greg Ross's Avatar
Greg Ross Greg Ross is offline
Grammar Curmudgeon
AKA: gwross
FRC #0330 (Beach 'Bots)
Team Role: Mentor
 
Join Date: Jun 2001
Rookie Year: 1998
Location: Hermosa Beach, CA
Posts: 2,244
Greg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond repute
Send a message via AIM to Greg Ross Send a message via Yahoo to Greg Ross
It's buried in this thread.
__________________
Greg Ross (The Grammar Curmudgeon formerly known as gwross)
S/W Engineer, Team 330, the Beach 'Bots
<--The Grammar Curmudgeon loves this cartoon.
ôLife should not be a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside in a cloud of smoke, thoroughly used up, totally worn out, and loudly proclaiming "Wow! What a Ride!" Hunter S. Thompson
"Playing a practical joke means doing something mean and calling it funny." Me
  #3   Spotlight this post!  
Unread 03-01-2003, 02:48 PM
Jnadke Jnadke is offline
Go Badgers!
#0093
Team Role: Alumni
 
Join Date: Jan 2002
Location: Appleton, WI
Posts: 775
Jnadke is on a distinguished road
Send a message via ICQ to Jnadke Send a message via AIM to Jnadke Send a message via Yahoo to Jnadke
The Banner sensors just use current sourcing, so it should be safe just to hook the Brown and Blue wires up to the battery as you would normally, and put the white wire to the EduRobot digital input (+).


The manual says the sensors need 10-30V DC to operate normally, so you might need to use 2 9V batteries connected in series for this to work.

Basically:
1. Connect the (+) terminal of one 9V battery (Battery1) to the (-) of the other 9V battery (Battery2).
2. Connect the Blue wire to the unused (+) terminal on Battery2.
3. Connect the Brown wire to the unused (-) terminal on Battery1.
4. Connect the white (or black) wire to the (+) on the EduRobot digital input.
__________________
The best moments of our lives fall in two categories: those that did happen and those that did not.

Last edited by Jnadke : 03-01-2003 at 04:10 PM.
  #4   Spotlight this post!  
Unread 03-01-2003, 03:41 PM
Lloyd Burns Lloyd Burns is offline
Registered User
FRC #1246 (Agincourt Robotics)
Team Role: Engineer
 
Join Date: Jun 2001
Rookie Year: 1997
Location: Toronto
Posts: 292
Lloyd Burns is an unknown quantity at this point
The Banner sensors' outputs merely take the input pin to ground. They might like more voltage than the EduBot battery has, in which case you could lash up some 9V batteries, and feed the sensor(s) approx 18 V.
  #5   Spotlight this post!  
Unread 03-01-2003, 04:05 PM
Jnadke Jnadke is offline
Go Badgers!
#0093
Team Role: Alumni
 
Join Date: Jan 2002
Location: Appleton, WI
Posts: 775
Jnadke is on a distinguished road
Send a message via ICQ to Jnadke Send a message via AIM to Jnadke Send a message via Yahoo to Jnadke
Quote:
Originally posted by Lloyd Burns
The Banner sensors' outputs merely take the input pin to ground. They might like more voltage than the EduBot battery has, in which case you could lash up some 9V batteries, and feed the sensor(s) approx 18 V.

It's considerably more complicated than that, but basically that's what I said. If they did that, they would most surely damage the digital inputs.


The problem with this solution is that you are crossing batteries (feeding power from the 9V batteries into the NiCD battery). One pole will become depleted much faster than the other pole. Although this shouldn't lead to any problems, it isn't a very good practice.
__________________
The best moments of our lives fall in two categories: those that did happen and those that did not.

Last edited by Jnadke : 03-01-2003 at 04:37 PM.
  #6   Spotlight this post!  
Unread 03-02-2003, 09:05 AM
Lloyd Burns Lloyd Burns is offline
Registered User
FRC #1246 (Agincourt Robotics)
Team Role: Engineer
 
Join Date: Jun 2001
Rookie Year: 1997
Location: Toronto
Posts: 292
Lloyd Burns is an unknown quantity at this point
No, you are not going to be "crossing batteries". The collector of the output transistor in the sensor is not connected to the sensor supply. The highest voltage in the circuit due to the sensor supply is at the base connection, typically 0.6 V above the common ground on the EduBot.

Essentially, the transistor is only a path for current from the input to ground, exactly like a relay contact (neglecting the saturation voltage of the transistor, around 0.2 V, typically). The sensor o/p is "isolated" from the the sensor supply, and run in a saturated condition, usually.

My comment that the sensor might like more voltage is based on the printed voltage requirements on the side of the sensor - "10-30VDC". Often, when connecting to counter-controllers (like the Omron H7BR I have recently been fiddling with), the sensor is connected to the controller's power supply which can be selected to either 12V or 24 V (in the case of the H7's). The designer of the sensor probably had a certain voltage range in mind for the circuit, and there could even be a regulator in the package to make the sensitivity setting repeatable.

The sensor might work at 7.5 +/- 1.5V from the NiCd, but the lessons learned may not be applicable to the Full-sized Bot. A trivial test with the IR sensors ("xxxD" not xxx"LV") shows that at 6 V, the "white piece of paper" detection range for the setting it was left at, is 1/2 the range of the same sensor at 15 V.
Closed Thread


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Q&A Discuss: Optical sensors with EduBot CD47-Bot Extra Discussion 2 03-01-2003 05:37 PM
Q&A Discuss: optical sensors CD47-Bot Extra Discussion 0 02-15-2003 09:58 PM
optical sensors acting strangely rosebud Electrical 10 02-02-2003 11:29 PM
optical sensors majormusic2005 General Forum 1 01-28-2003 07:37 PM
EDUbot Sensors marlon_jbt Robotics Education and Curriculum 11 12-19-2002 12:38 PM


All times are GMT -5. The time now is 11:30 PM.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi