Jon
Guest
Tue Mar 02, 2010 6:05 am
I don't know the difference between a pnp and an npn, but I had a
transistor. All I knew was the middle terminal acted like a valve for
current to pass between the outer terminals. So how did I find out? I used
a pot to find breakdown, replaced it with an equivalent resistor, and went
from there. All I know from there is when the base was grounded, it opened
the valve, and I had my circuit.
Later I was working with a reed relay. Apparently the coil was polarity
sensitive, so I figured that one out and I had my circuit. That doesn't
count all the time I spent trying to use a transistor. This time it failed.
The voltage on the radio speaker wasn't enough.
So now I have two clocks, one with a fire alarm bell and the other with a
fire alarm buzzer pending shipment. When it gets here I can just
conveniently plug it in to the extension cord female dangling off the back
of the clock.
If there's a mistake that can be made, I will routinely make it.
Mistake Crusader Jon from Ohio
John Fields
Guest
Tue Mar 02, 2010 3:53 pm
On Tue, 2 Mar 2010 00:05:01 -0500, "Jon" <jon8338_at_peoplepc.com> wrote:
Quote:
I don't know the difference between a pnp and an npn, but I had a
transistor. All I knew was the middle terminal acted like a valve for
current to pass between the outer terminals. So how did I find out? I used
a pot to find breakdown, replaced it with an equivalent resistor, and went
from there. All I know from there is when the base was grounded, it opened
the valve, and I had my circuit.
Later I was working with a reed relay. Apparently the coil was polarity
sensitive, so I figured that one out and I had my circuit. That doesn't
count all the time I spent trying to use a transistor. This time it failed.
The voltage on the radio speaker wasn't enough.
So now I have two clocks, one with a fire alarm bell and the other with a
fire alarm buzzer pending shipment. When it gets here I can just
conveniently plug it in to the extension cord female dangling off the back
of the clock.
If there's a mistake that can be made, I will routinely make it.
---
Murphy's Law, but sometimes it's a blessing:
http://en.wikipedia.org/wiki/Buttered_cat_paradox
JF
