110V transfer

[airman00]

I need to charge a robot with a regular home plug but how can I have the robot back up.

Do i put plates that are activated by IR only when the robot is close enough. I want the robot to back up into the charging plates. How can I do it safely , without electrocuting anyone.

[SmAsH]

is it possible to set for how long he backs up like times and distance?

[ed1380]

he's asking the questions 



the robot doesnt need to back up. it can drive in forward (easier) and then just back out and turn .

you can either put the transformer on the robot(IMO not best idea) or have it with the base.

i would personally put a bright IR led at the base and IR photosensors on the robot w/ photovore code

[Ro-Bot-X]

I have been thinking about this and perhaps the best way to do it is to halve the transformer. Install the primary coil in the charging station and the secondary on the robot. Kind of like the rechargeable toothbrush. You will lose eficiency, but will not electrocute anyone.

Another way would be to separate a switching power supply because it allready has 2 circuits connected through optical couplers, if I remember corectly.

Or, just use a transformer with a high enough voltage in the secondary coil, make contact plates, then regulate different voltages onboard the robot.

[airman00]

I was thinking of having coils ( one on robot and one on charger ) after reading about it in PopSci yesterday

But where would i get such big coils that could transfer 110V and how much loss of power would i get from the primary coil in the wall to the robot's coil?


If not ill add contact plates for 110 V that are activated by IR sensors on the robot itself , so no accidental electrocution.

[ed1380]

why not have teh plates be only like 7v? no electrocution if shorted and you can still add a fuse

[airman00]

why not have teh plates be only like 7v? no electrocution if shorted and you can still add a fuse

because my setup is as follows 

one system powered by two 12VDC 20ah batteries and another seperate system which is a laptop powered by its battery

Now either I interface the laptop to the batteries directly somehow or I charge them with their respective AC adapters

any ideas ?

[ed1380]

ahh. i see.

12v charger for the laptop 

[SmAsH]

is the laptop the thing that runs chives? or is there a whole other micro chip? because if theres just the laptop then use the cable that came with it.


~smash

[airman00]

laptop runs chives

what I want is for chives to self charge when he needs it , so assuming I work out the problem of chives finding his charging base ,  how can I have CHives back up to charge

The way it is now I would need four charging plates for him to charge with. So what I would do now is connect the AC adpater for both the laptop and for chives together to have two connections which need 110V from a standard home outlet. Then I would have the plates give out electricity only when chives is docked to it ( so noone accidentally gets electrocuted when chives is not charging)

[ed1380]

those 2 12v batteries. are they in series or parallel?

[airman00]

12V in parallel

I dont know how to connect the batteries to the laptop properly if thats where you are headed at

[Ro-Bot-X]

I bought a car power adapter for laptops. When the laptop battery gets almost depleted, a 12V relay connects the power adapter to the robot's 12V battery. This way I need to charge just the motors battery. And the laptop battery keeps my laptop on for about an hour and half, but the motors battery only lasts about an hour of continuous run. But be carefull, cut the cable that goes from the power adapter to the laptop and hook it to the relay. Better use a DTDP relay and connect both ends of the power adapter to it. Some laptops batteries get discharged if the laptop's power adapter is plugged in to the laptop but not to the wall socket.

[airman00]

yes but that car power adapter is an inverter or not

if its not an inverter than where can I get it from ?

[SmAsH]

do you know how to make him know when he has low battery? if you do then you could have some sort of switch???


~smash

[airman00]

do you know how to make him know when he has low battery? if you do then you could have some sort of switch???


~smash

that part I know  , the problem I have is interfacing the laptop's battery with the motors battery.
Now what RobotX is talking about suits my needs, I just need to find a power adapter for batteries thats not an inverter ( since thats just wasting power) . Just a power adapter thats for laptops only . DC -DC not DC-AC and then I would convert it to DC again

Know of any power adapters , anyone for laptops?

[HDL_CinC_Dragon]

why not just go to a store, pick up a 12volt battery charger that plugs into the wall, connect the output to the charging plates on the base and plug it into the wall. Then have some kind of simple pressure switch that when pressed (such as when the wheels run it over or you could use a simple IR circuit and have an IR LED on the bottom of the bot facing the ground and an IR detector on base looking for an IR signal above it), charges the positive plate on the base with 12 volts (not enough to shock anyone) and those then contact the charging plates on the robot?

[Ro-Bot-X]

Here is a sample for a Dell laptop (I have a Dell). It's a DC-DC switching power supply.
http://www.techforless.com/cgi-bin/tech4less/PA357U?mv_pc=yahoo_ssp

[SmAsH]

yea i think my parents laptop has that...moving along....how big are plates? and arent those adaptors easy to get like from old electronics? ive got tones lying around i think ive got 2 4.5V 3 9V and 1 12V. anyway good luck finding one....(maybe look on ebay)


~smash

[ed1380]

12V in parallel

I dont know how to connect the batteries to the laptop properly if thats where you are headed at

the power cable for the laptop that runs off the cigerette lighter