That sounds like a full-wave rectifier, which is 4 diodes and would increase the LED duty cycle. The post I was replying to seemed to indicate using a single diode.
Note that the duty cycle is not 100%, considering the time voltage is below about 3.4V (forward LED drop plus 2 Si diode drops).
You can buy all the diodes you want at Radio Shack. My "musical doorbell" (electronic) came with both the instructions detailing the need for a diode as well as a little package with two diodes in it.
when buying diodes higher current rating and voltage never hurts. in continious duty the higher current rating is usually larger physically which helps keep it cool for long trouble free operation.
generally doubling voltage and tripling current rating is a good idea, plus diodes are very cheap:)
The only time there is any significant current is when the doorbell is ringing. It's a pretty short duty cycle. I"m not disagreeing with your general statement but this is not a very stressful application.
How long do the batteries last? Are the batteries changed from the inside or from the outside?
my keypad lock has battery life over a year, which is fine. the batterys arent charged.
if the electronics fail for any reason the key still works in manual mode..
I had some work being done here, I asked the contractor what PIN he wanted and deleted it when he was done:)
the best 100 bucks I ever spent:) At night pushing a button brings up all the buttons lights:) for easy button pushing:)
I put a similar setup on my front and side doors a couple years ago. Like you, haven't used a key since - stopped even carrying one as I have hidden ones for emergencies. Wish I'd added these 30 years ago. Now that I'm practiced I can open the lock faster then using the key.
I think there's one out that has a thumb print reader? I want the one with the robot eye on a stalk that pops out of the door to look me over then scan my irises or retinas. I seem to remember a movie "Gattaca" where the access control to office buildings required a blood sample to verify your DNA. The line of workers coming into a building stuck their index fingers in a gizmo that popped a needle into the finger to get a blood sample. Ouch! ^_^
TDD
ME TOO, the fast entry is really nice in rain:( freezing weather:( and when you just HAVE to go to the bathroom:(
Is there a limit to the length of the PIN? If there is, what is the limit? Is there a limit to the number of active PIN numbers that you can have at one time?
Does the keypad have letters on or near the numbers like a telephone keypad? (I find it easier to remember a word than to remember a number.)
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