i hate to post this question publicly, but my searches have been fruitless, and i'm not yet familiar enough with the members of the forum to know to whom i should directly address my questions.

the Power Functions power point is clearly different from that of the earlier electrics design. still, i've seen a couple of examples of the old and new being mixed. is 8886 an adapter cable for this purpose? is there a way to make the two compatable without an adapter cable and without cracking open the connectors, say with redundant cabling?

also, i've been looking at the PF battery box. the single-button on/off suits my needs better than the deadman's switch found on the earlier designs. one aspect of the older design that i don't like is the amount of pressure needed on the buttons to fire the battery box. does the new sinlge button require as much force to fire the box? is it less or more?

any insight would be greatly appreciated.

KEvron

Yes, the 8886 "Power Functions Extension Wire" (first picture below) can be mixed with the old-style 5306b "Electric, Wire with Brick 2 x 2 x 2/3 Pair" (second picture below). The old-style 2x2 electric plate fits on the UNDERSIDE of the new PF-style electric plate.

The official Lego Power Functions website has answers to many "Frequently-Asked Questions" (FAQs).

Compared to the old-style 2847c01 Lego Battery Box (with the red button), it takes a lot less pressure to activate the green button on the PF Battery Box (whether it be the 84599 "Electric 9V Battery Box Power Functions (Rechargeable)" or the 87513c01 "Electric 9V Battery Box Power Functions (Non-Rechargeable) with Dark Bluish Gray Bottom").

once again, D proves himself to be the go-to man! thanks, again, bub.

KEvron

has anyone cracked the PF battery box 88000? i'm trying to devise any auto-wind for my clocks, and i'm finding that the on/off button requires more actuating pressure than suits my design. i thought i might crack the box and cut back the button spring a bit, if there is one. insights?

KEvron

@ KEvron: It could be that the innards of the Lego 88000 Power Functions AAA Battery Box is similar in function to the PF AA Battery Box opened up on the Philohome website. Of course, you can contribute to science by dissecting your PF AAA Battery Box and posting the pictures!

88000 Power Functions AAA Battery Box is similar in function to the PF AA Battery Box

no, 88000 has the green on/off button.

Philohome website

no answer to my question there, but i did find the answer to an as yet unasked question regarding reducing the battery count in order to reduce the voltage output. thanks for that.

Of course, you can contribute to science by dissecting your PF AAA Battery Box and posting the pictures!

<anxiously fidget> me?! i, uh....er....i would, uh....um....</anxiously fidget>

KEvron

Edited January 19, 201213 yr by KEvron

i'm finding that the on/off button requires more actuating pressure than suits my design.

Have you considered using the bb339c01 Electric, Pole Reverser?

Of course this would mean that the LED is always lit on the battery pack, but with a converter cable you could perhaps use the old style small 9V battery box? Or just use the old style 9V components all the way for that matter...

Have you considered using the Electric, Pole Reverser?

i've given that element a look or two. does it have an "off" position between the two directions? i'm firing the battery box only intermittently; continous power wouldn't work for me.

here's the thread on the project for which the box is employed.

KEvron

Yes it does

the Power Functions power point is clearly different from that of the earlier electrics design. still, i've seen a couple of examples of the old and new being mixed. is 8886 an adapter cable for this purpose? is there a way to make the two compatable without an adapter cable and without cracking open the connectors, say with redundant cabling?

also, i've been looking at the PF battery box. the single-button on/off suits my needs better than the deadman's switch found on the earlier designs. one aspect of the older design that i don't like is the amount of pressure needed on the buttons to fire the battery box. does the new sinlge button require as much force to fire the box? is it less or more?

I'm not sure what you actually are looking for, but if it is a way to turn of and on some power to the old 9v system with a light touch maybe you can use the http://www.bricklink.com/catalogItem.asp?P=879 Electric Touch Sensor (ment for the Mindstorm RCX). If do remember it correctly you could wire it up so it would work as a powerswitch. When pressed the power goes trough and when released the power disapears. And the spring in this is very fine and you don't need much pressure to activate it.

The green button on the new PF battery box (AAA or rechargeable) is also very light. One press for on, another press for off. The difference is that on the rechargeable one you can set the power you want out with the little orange dial. On the AAA box you can only switch direction of power.

What type of motor are you going to use for this?

maybe you can use the Electric Touch Sensor (ment for the Mindstorm RCX). If do remember it correctly you could wire it up so it would work as a powerswitch.

i would kill for that schematic!

The green button on the new PF battery box (AAA or rechargeable) is also very light. One press for on, another press for off.

i've recently purchased that element. i've discussed its properties on this thread.

What type of motor are you going to use for this?

47154, shown in video in the aforementioned thread.

Yes it does

hmmm. interesting. what kind of kinetic resistance does the switch offer? is it rather stiff, or just enough tension to hold its position? i'm using the drive train in my clock to actuate, so irregular torque is a concern.

KEvron

Edited January 20, 201213 yr by KEvron

... i would kill for that schematic!

KEvron,

F0NIX suggestion may only work for low currents though; the Touch Sensor has a resistance of about 500 Ohm when closed (pressed) and when you run some current through it "generates some heat", at least this is what I found out when using such a switch for powering purposes.

Regards,

Thorsten

when you run some current through it "generates some heat"

then i consider myself fairly warned.

this is what I found out when using such a switch for powering purposes

ah. could you provide the schematic? is it done with simple in-line connections, or must the sensor be hacked?

KEvron

Edited January 20, 201213 yr by KEvron

@ KEvron: This website says that the Lego Touch Sensor "consists of nothing more than a contact switch held open with a spring and wired in series with a load resistor":

That website talks about the switch "bouncing" its signal when depressed; recommend that you read it.

"consists of nothing more than a contact switch held open with a spring and wired in series with a load resistor"

ah, so it's a simple open/close switch. good to know.

That website talks about the switch "bouncing" its signal when depressed

i suspect that's only of concern when used as a sensor. the rcx would transmit a passive signal (nomenclature?) through the device, which would be subject to that bounce, while i intend it as a remote power switch.

all this still leaves me wondering how to implement the device into the circuit F0NIX suggests (battery box, motor and touch sensor). i have to admit that i'm not very electronically inclined. i suspect some redundant wiring is involved, in order to isolate the polls on the sensor's single connection point. i don't own a sensor, and most of the few electrical elements i do own are visible in the auto-winder video, so i'm not in a position to experiment. i need to know the layout before i drop some scratch.

KEvron

KEvron,

F0NIX suggestion may only work for low currents though; the Touch Sensor has a resistance of about 500 Ohm when closed (pressed) and when you run some current through it "generates some heat", at least this is what I found out when using such a switch for powering purposes.

Regards,

Thorsten

The blue ones contains different resistor values. But the grey one for the RCX does not contain any resistor. I have measured them. And I have also seen pictures of them opened some place...

But you are right about that they are not made for high power as there are very small contact areas in the switch. But powering just one motor should be fine.

I'll try to find a drawing for how to connect them to use them as power switch on a wire.

Uh.. I actually have to correct myself there. There IS a resistor value in the 879 Touch sensor. But on the units I have it varies. Mostly around 1.5k Ohm and up to 2k Ohm. But there is no internal resistor to be seen inside. I don't know how the blue sensors look like internally so I don't know how they manage the different values in them. But in this it seems to be inside the black rubbery connector piece in the middle. (See pictures below)

Anyway, I opened one and quickly found an easy way to modify it to to be a true power switch without any internal resistor value. All you need is a 879 Touch sensor (duh!), one small flat screw driver, one small strip of aluminum foil. Look at these pictures:

Open the touch sensor by prying the small flat screw driver in between the DBG bottom part on the side and bend the sides of the top LBG part out. Do this on both sides and the bottom part should pop out easy. This is the three part separated. Cut a little piece of aluminum foil on the size as on the picture here.

Stick the aluminum foil in under the black rubbery center part. And wrap the foil around it. The end to the left on this picture is the contact points.

Put the yellow button part in and snap the top back on the bottom part. And volia! You have made a powerswitch out of a touch sensor! :)

And this is how you connect it in between a batterybox and a motor. You just need a short 9v lead to make the connection. The switch only breaks one of the two leads to the motor.

(Click on the images to see larger versions)

thank you, F0NIX, for going the extra mile. you're too gracious. and thanks to the rest of the forum for their input.

KEvron