There are no zener diodes.There are zener diodes on the schematic after the switch? What V rating are they?
Ok thanks for the clarification.They are not Zeners. They are Schottky diodes.
You could use 1N5821 or 1N5822 Schottkys, or other >=2A Schottky diodes.
Sorry, I read the symbol wrong. They are similar looking when small.There are no zener diodes.
Sorry. I didn't know you looked at the schematic on a tiny cell phone.They are similar looking when small.
Hmm well my phone isn't exactly small... its about the same size as the dell streak.Sorry. I didn't know you looked at the schematic on a tiny cell phone.
It never hurts to have a few extra on hand.Alas, I have but 1pc of the 5844... Such is life, however, I will need to pick up the 555 Timer and the mosfet anyway, so I might as well grab a 4pk of the schottky 5822's.
I forgot about that.I wanted to put a power indicating led (red 3mm 2.2Vf @ 10mA) Can I place this between the switch and the 555 timer? It is so I can see if the unit is on or not, being IR leds, I don't want people looking at it when it is on full blast... preventative measure.
You can use just about any small-signal NPN transistor; 2N2222, 2N3904, 2N4401, etc - it does not have to sink much current to keep the 555 timer disabled and the output switched on.I found a transistor comparable to the bc... it is an NTE123AP, datasheet located here http://www.nteinc.com/specs/100to199/pdf/nte123ap.pdf
I think it is higher in capacities, but will still do the job I am hoping.
Ok so the test board circuit was made and it working using only a single string of 1.42V irleds. The question I propose is this, looking at the led strings you have arranged them in 7 -led strings and the last 4 strings are 6 leds... what values did you use to calculate the series resistors for each string?Sorry - there's a lot of people needing a lot of help; things tend to fall through the crack.
Have a look at the attached. I didn't have a 3-position switch, so I used two SPDT switches. Don't let that throw you.
You'll only have one common switch terminal; represented by the left side of S1a and S1b.
The dim side is represented by S1a. When it is selected, the 555 timer runs, and the brightness is set via VR1.
The bright side is represented by S1b. When it is selected, the 555 timer is prevented from running by R15 pulling up the base of Q1, which keeps C1 from charging, which keeps the output of the 555 timer high, which means the LEDs are on all the time.
Use the values that were calculated some many posts back when I had you using 8 in series.Ok so the test board circuit was made and it working using only a single string of 1.42V irleds. The question I propose is this, looking at the led strings you have arranged them in 7 -led strings and the last 4 strings are 6 leds... what values did you use to calculate the series resistors for each string?
*BUMP* - Sgt.Wookie, can you advise on the led order you used? I cannot get the value resistors that you did, Thanks!