Joined: 19 May 2010
Posts: 3973
Location: ipswich QLD
two Limit switches and one tz85 diagram
Is this possible to do?….we been using two relays attached to a botbitz esc and limit switches to control pickasso's winch pick…..it works but intermittently stops after a few hits…so thought we would try a tz85 but not sure how to make it work with two limit switches…can get it to stop with one limit switch …but how to connect two limit switches?…….any diagrams you guys can suggest? _________________ Miles Blow - Julie Pitts
www.mulesfilm.com.au www.wombokforest.com.au
-Pickasso- Vivid Sportsman champion 2015
Mon May 11, 2015 5:01 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
How are you wiring up the limit switches and what sort of current capacity do they have? Many switches will be rated to carry a certain number of amps but do not like actually switching on or off with that level of current running thru them. The switches may have burnt-out contacts after a few cycles - can you test / open a used switch to check the contacts? _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Mon May 11, 2015 5:49 pm
James2
Joined: 07 May 2015
Posts: 115
Location: South Australia
I can email a wiring diagram to you, that uses limit switches and then separate contacts to carry the current. (its for a roller door but its the same circuit) i'm adapting it to my bot.
I will have my modded one for my bot done by tomorrow and happy to send that with a parts list.
Mon May 11, 2015 7:11 pm
RogueTwoRobots
Joined: 12 Jan 2008
Posts: 135
Location: Irvine, Scotland
I had this problem years ago when I had a crude electric axe powered by a windscreen wiper motor. Could get it to work with two limit switches when using the 'bang-bang' control approach but couldn't work out how to do it with a proportional ESC. Found this a few years later:
Used it on my horizontal crusher (well, grabber ) to good effect, although because the actuator moved so fast, there was a split second delay between it hitting the switch and the switch breaking the circuit, so there is still a risk of slight damage (either to the weapon source or the switch if they're little/cheap ones) but better than having nothing. _________________ Jamie
RogueTwo Robots
www.rogue-two-robots.vze.com
With great power, comes great reliability
Mon May 11, 2015 8:12 pm
James2
Joined: 07 May 2015
Posts: 115
Location: South Australia
wow, I have really over complicated mine (had a controller unit built in).
Mon May 11, 2015 9:02 pm
miles&Jules Experienced Roboteer
Joined: 19 May 2010
Posts: 3973
Location: ipswich QLD
Joined: 19 May 2010
Posts: 3973
Location: ipswich QLD
Jaycar has 18v 1watt diods- how much wattage would it need? Should we try them and see what happens- we are running 4s 2000ah _________________ Miles Blow - Julie Pitts
www.mulesfilm.com.au www.wombokforest.com.au
-Pickasso- Vivid Sportsman champion 2015
Tue May 12, 2015 12:11 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
The diodes could take quite high currents for a short period while the switch closes; it depends on you motor, gearing and how much weight is being lifted. I'd play it safe and go with 6A diodes. If you blow a diode, you can always run 2 or 3 in parallel to share the current. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Tue May 12, 2015 12:17 pm
Knightrous Site Admin
Joined: 15 Jun 2004
Posts: 8511
Location: NSW
Alternatively, look at raiding some diodes from a car alternator, IIRC some of them extend into the 30-40A range depending on the model. _________________ https://www.halfdonethings.com/
Tue May 12, 2015 12:36 pm
miles&Jules Experienced Roboteer
Joined: 19 May 2010
Posts: 3973
Location: ipswich QLD
Sounds like s good source aaron-we just tested it with a 775 motor and it works perfect now to see what happens with the winch _________________ Miles Blow - Julie Pitts
www.mulesfilm.com.au www.wombokforest.com.au
-Pickasso- Vivid Sportsman champion 2015
Tue May 12, 2015 12:50 pm
miles&Jules Experienced Roboteer
Joined: 19 May 2010
Posts: 3973
Location: ipswich QLD
Joined: 07 May 2015
Posts: 115
Location: South Australia
this one is auto reversing.
here is one that uses 2 relays (one to take the current for one limit switch).
K1 is a DPDT (double pole double-throw)
S2 is the lower limit switch.
K2.1 is the upper limit.
can just add the speed controller to the start of the circuit. (can remove Rx1 &Rx2 with a ESC)
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Sat May 16, 2015 10:58 am
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