soldering a wire to a pin on PCB

[BuddingContraptionist]

I've tried twice now to put together a simple little circuit on PCB.  I have a 14 pin socket that i've soldered to the board, a 5v regulator, pins to plug the battery to, and a resister/LED to prove that it works.  So I solder the pins that the battery connects to across to the 5v regulator, and then run a wire from the output of the regulator to the microcontroller.  but when i read the voltage coming across from that pin, it's like 4.63v.

How do you get a really good wire to pin solder joint?  I haven't tried flux yet, i'm just heating the two metals and applying the solder to them.  I simply wrap the exposed part of the wire as tightly around the pin as i can manage, but i figured the solder would conduct electricity.  btw it's a "silver-bearing solder".  Should i maybe get one of those little solder clamps and some flux?  Or is there a trick to it?

[szhang]

Just about all solder contain flux.  Just the fact you're reading a voltage means the solder joint is conducting.

What is the voltage on your battery, and what regulator are you using?  Most regulators have a voltage drop, so if you use 6V battery with a 5V linear regulator, you'll probably see <5V output.

[BuddingContraptionist]

it's a 5v nimh battery, i read like 5.7 off of it directly.  When I was testing out the regulator i just taped the wires to the pins and thought i read out a steady, exact 5v from the output pin.  I was just thinking my soldering was subpar.

But after some reading it looks like the LM7805 has a voltage drop of about 2 bolts.  I have an axon which appears to have just an LM7805, and when i plug my battery onto that it works fine.  What am i doing wrong?

[Ro-Bot-X]

Actually, the Axon uses a Low Dropout voltage regulator, L4940V5 is written on mine. This means that the battery voltage has to be about 0.5V higher than the regulated value. If it is less, the regulator is bypassed. So, from your 5.7V battery, the Axon will get a steady regulated 5V, but the LM7805 will not get it right.

[airman00]

its probably a 4.8V or 6V battery pack since rechargeables go in multiples of 1.2

If its 6V you're in luck , and you just need to charge it

[BuddingContraptionist]

eh i got some low drop voltage regulators from mouser.  thanks for the heads up