Apple Bluetooth Mod: Voltage regulator question for gurus

[InvaderSteve]

A (hopefully) simple question for for any electronic gurus out there.

Will any 3.3v voltage regulator work for the Apple Bluetooth hack? There are many references to the TS1117 3.3v voltage regulator (which is only available in Europe) and one to the LM1117 3.3v. I live in the US and don't want to wait 3-4 weeks for something from Thailand to ship, so I was interested in the following on eBay:

L78L33ACZ 78L33 + 3.3V Voltage Regulator IC TO-92

1117 3.3V 1117-3.3V Voltage Regulator TO-223 SMD

LM1117 Low Dropout Voltage Regulator 3.3V 800mA

I'm leaning towards the third one, but I wanted to make sure.

An unrelated question, I'm going ahead with the Apple wifi mod and have ordered the standard Mini PCI-E to PCI-E Wireless adapter with 3 antennas. After I detach it, will the spare antenna work with the Bluetooth module's SMA connector?

Thanks for your help.

 

[BigDubbe]

Third one with a heat sink would be the best.

 

[minihack]

Really don't know why you just don't go for "the diode method" as discussed in the main thread for this.

Two diodes are cheap and are really all that is needed. The bluetooth module is a very low power circuit and certainly does not need its own voltage regulator and heatsink.....

To sum up: diode method is basically get two really cheap diodes (such as: 1N4001) and wire them together so that they are nose to tail (i.e. both facing the same way) and wire them into the 5volt supply line going to the bluetooth +v input.

Explanation

Diodes can be thought of as a component that passes everything through it like a straight piece of wire, but which only allows electricity to flow in one direction. That is why diodes have a electrical symbol that looks like an arrow.

The electrical current passes only in the direction of the arrow.

Each diode however, because of the material from which they are formed, reduces the voltage supplied by 0.7 volts. So if you put a diode between 5v and a circuit, the circuit gets only 4.3v. If you then put a second one in the circuit gets 3.6v.

3.6volts is not going to blow up the bluetooth module and it will work very happily for the life of your computer like that (all other things being equal!).

So, buy two cheap signal diodes and then wire them like this:

+5v wire

+v on the bluetooth module.

By the above I mean that the end nearest the 5volt line (on the left in this picture) is the "Anode" of the first diode and the end nearest the +v input (on the right) for the bluetooth module is the "Cathode" of the second diode.

This page http://www.kpsec.freeuk.com/components/diode.htm explains in more detail about what diodes are and what is meant by the anode and cathode. Basically though the anode is where the electrical current goes in and the cathode is where the electrical current comes out.....

Here are 20 diodes for 99pence! - enough for 10 circuits......

In the end, it is your choice but the money you save I am sure can easily be spent on another mod.!

 

[akhilv1]

Could you, in theory, use the 3.3v supplied by pins 1,2, and 3 (Orange cable) from SATA power for this?

 

[dominic714342]

Could you, in theory, use the 3.3v supplied by pins 1,2, and 3 (Orange cable) from SATA power for this?

I did exactly what you described, but the problem the computer wouldn't sleep properly doing so. The computer will immediately wakes up after sleep. I looked up the system console, the computer was waken by the BT module.