Polarity Protection in RM

[formerMember1]

Hi,

Just wanna make sure of something, :wink:

I am building a RM by geofx, with terminal strip, with dc adaptor jack,
I want to put in power filter(i got a100uf cap) and Polarity Protection(1N4002)

For the PP do i just put it in with the power wire coming from the terminal strip to the 3pdt switch? The pedal is PNP so i guess i would put cathode to - and anode to +   but, what does that mean?  Cuz i have the power wire(-) coming from the terminal strip to 3PDT lug, then from same lug i got a wire going to the adaptor jack, so where does the PP diode go?


thanks :wink:

Also,
Where would i solder the Power filter cap to? Remember this is a PNP pedal with terminal strip ,LED and 3PDT.  

Fretwire helped me out with this months ago, but that was only for battery use, now i am using battery and DC jack, so now i am confused.  I am more confused since this is PNP not NPN.  

Will the Power filter cap take any volts from my battery or adaptor jack?
I hope not since i already have bias resistors soldered to terminal strip and i am ready to mount pedal together.

thanks again, and i realize this post is alot to ask of, :wink:

[petemoore]

A power protection diode 'points' toward the red battery lead, wherever that may go. The kind that go across the rails at least, which is the wiring I use.
 The - of a polarized cap always goes to it's most negative connection point in a circuit...

[formerMember1]

power protection diode 'points' toward the red battery lead,

So does that mean i put the PP diode in series with the red battery lead? If so, Does that mean i will still have PP protection whether i use DC jack or battery?

The - of a polarized cap always goes to it's most negative connection point in a circuit.

So i put that in like a pulldown resistor would go then?  Like the negative power wire and the positive end of cap to ground on stereo input jack or output jack ground?

thanks petemoore

[petemoore]

For examples of Polarity protection diode in circuits check out Fuzz Central.
 So i put that in like a pulldown resistor would go then? Like the negative power wire and the positive end of cap to ground on stereo input jack or output jack ground?
 I can't follow that, perhaps restating it using a schematic and component identification for reference, one component [or section] at a time please...we've got *polarized caps 'somewhere', *negative power coming from somewhere witha *cap mixed in somehow and jack ground lugs and also *pulldown resistors?
 Starting with the polarized cap, what position is it in, and in what circuit?

[formerMember1]

Sorry Petemoore you are right that is kinda hard to understand, :oops:

Lets first start with the Polarity protection diode:

The pedal is a RM, wired with 5 lug terminal strip, boost pot, in and out jacks, 3pdt w/LED and DC adaptor jack from smallbear, also a battery clip.

I am wiring the DC adaptor jack in pedal now, (not soldered just running wires  till i am sure then solder  :wink:  )

Where would the PP diode go?  In series, parallel or one end to ground?

I am trying to figure it out, so that i have polarity protection with adaptor and battery.

So would the PP diode go where?

I have read Fuzzcentral many many times, I am still confused by this,
I understand it is very simple, but i am just very boggled by it :roll:

thanks for your time petemoore, i appreciate the help and time. :wink:

[formerMember1]

On a follow up,

I have one lug of dc jack going to 3pdt switch for LED power switching, as  KORGULL helped me with.(middle top lug of switch) (there is also a wire coming from circuit to this lug on 3pdt, that is the way my circuit gets power)  I  have a lug on adaptor jack where my negative(black) battery wire would go, then the positive(red) wire from battery goes to ring of stereo jack.  The "big" lug on the adaptor jack is supposed to go to ground on the stereo jack.

So my pedal now would work(hopefully) since it would recieve power by either using a battery or adaptor.
But i want to add the PP diode to protect from battery or adaptor wrongdoing, as mentioned in previous post. :wink:
So where do i put the diode?

I hope this helps clear up some of my "sloppy" posting,  :wink:

[formerMember1]

So far what i found out by researching for an answer for the Polarity Protection diode,  for a PNP pedal, is i put the cathode(mark) towards the adaptor jack and anode(no mark) to circuit.  I assume this is a series connection.

If you looked at an adaptor jack with the lugs facing you, and the big lug on the bottom , I guess i would put the PP diode in series to the top lug, which goes to my 3PDT switch,  But would that also protect battery backwards polarity?  Is the above correct?

thanks :wink:

As for the Power Filter cap,(100uF electro) i have no idea what to do. Except i am only guessing here, but i put the positive end of 100uF cap to ground and the other end to where?

thanks again Petemoore and others :wink:

[petemoore]

The PP Diode goes across the power rails, which is battery clip Red 'n Black which is also V+/V-.
 The diode has an 'arrow' or V shaped figure in it's code marking, the one that's 'pointing' into the 'cross line' on paper...should in your circuit physically 'point' toward the Red Lead of the Battery Clip...
 So you have the diode pointer side hooked up to the red of battery

• clip and the other end connects to the black [-] battery lead...done...But..I solder the diode somewhere onto the board, usually right around where the battery leads come to it.
   As far as a DC PS Jack on a "RM" [rangemaster?]...unless you're using a Spyder for PS your'e probably not going to like the performance and noise introduction.
   Then anyway I don't use DC Jacks, let alone wiring it in a POS Gnd circuit, best I not try offering other than use a DMM to check for shorts across V+/V_ with plugs inserted in any jacks involved with PS Switching and guess you might want to use an insulated jack from a metal box with the Pos connecteion to ground for shielding.

[KORGULL]

I don't know if this will help or complicate things even more for you, but did you read these articles by R.G. yet?:
http://www.geofex.com/Article_Folders/cheapgoodprot.htm
http://geofex.com/Article_Folders/mosswitch/mosswitch.htm

Put the filter cap directly across power and ground. For negative ground pedal, put the cap + to power and - to ground. Reverse for positive ground circuit.

You can put the diode across power and ground, but reverse the polarity so it only conducts if the pedal's power polarity is reversed.
If you accidentally hook the battery up backwards the diode will be forward biased now and will present a path with little resistance for the current to flow - diverting it from the rest of the circuit.

If you put the diode in series (forward biased) right after the power supply and the power polarity is reversed, the diode will then block the current from flowing through the circuit.

I think this is probably all covered in R.G.'s articles so check 'em out - I think I'm going to re-read them myself now.

[formerMember1]

Put the filter cap directly across power and ground. For negative ground pedal, put the cap + to power and - to ground. Reverse for positive ground circuit.

Hey korgull,
Does it matter which  ground i connect the + end of PF cap to?  Like could i connect it to the output jack's ground?  I don't have any more room on the terminal strip's main ground, and there is wires running to both jacks'(in and out) grounds anyway.  Plus there is no room left on the input stereo jacks sleeve(ground) i already have a pulldown R, a LED ground, and Polarity protection to that ground point.

PS:I guess i should put the Power filter cap after the Polarity protection, so that in case of reverse polarity problems or what ever, my power filter cap won't get blown, right?

thanks again, KORGULL

Power filter caps don't take any voltage from the battery or anything, right?  Is there any draw backs to having a power filter cap in a Rangemaster or any other pedal? 

[gaussmarkov]

hey formerMember1,

i was working on this kind of question when i posted this power filter thread recently.  i put a schem there.  does this help?  R1 and C2 are optional.  many put the diode after R1.