Show Posts
Pages: 1 ... 28 29 [30] 31 32 ... 183
436  Using Arduino / General Electronics / Re: Question with level shifter CD4504B on: March 15, 2014, 06:40:41 pm
I was thinking

5v to base.
Collector goes to gnd (ic pin)
Emitter to gnd.

(Resistor required)

5v signal turns on the ic, 0v turns it off.



437  Using Arduino / General Electronics / Re: Question with level shifter CD4504B on: March 15, 2014, 08:47:57 am
How about a transistor?

When 5v is present on the base pin, the 12v is "on" no 5v signal, 12v is off?..
438  Using Arduino / General Electronics / Re: Is it possible to break specific output pins of a 8-bit shift registry? on: March 15, 2014, 05:59:32 am
I only swap them if they are misbehaving... if that cures the problem bin the faulty one.
439  Using Arduino / General Electronics / Re: Is it possible to break specific output pins of a 8-bit shift registry? on: March 15, 2014, 05:36:28 am
595's damage easily .. a little over voltage and I've had them die or just random pins.
440  Using Arduino / General Electronics / Re: Question with level shifter CD4504B on: March 15, 2014, 05:28:37 am
A 5v zener diode from the constant 12v would work or a 7805...

441  Using Arduino / General Electronics / Re: 3v Pager Motor Powered By 9v Battery on: March 13, 2014, 03:40:40 pm
A linear reg would waste a lot of the 9v as heat.

A voltage div would fail to give a regulated voltage and not deliver enough current

442  Using Arduino / General Electronics / Re: power leds driver on: March 09, 2014, 09:03:03 pm
I'm not saying you should, I'm intrigued by fungus' s comment, It's not as wasteful as he might think.

(Vin - Vf(LED)) * I = power wasted. You can make up any arrangement of mosfets, bjts, or resistors that you like but the above formula still holds true.


I'm refering to the waste of the transistor (heat dissipation) ...
443  Using Arduino / General Electronics / Re: power leds driver on: March 09, 2014, 04:38:49 pm
Everycircuit for android and ios....

444  Using Arduino / General Electronics / Re: Hot/Cold Fault Finding... on: March 09, 2014, 10:43:13 am
Why would it?

Stick the electronics in a freezer = never break?
445  Using Arduino / General Electronics / Hot/Cold Fault Finding... on: March 09, 2014, 09:41:08 am


I found this video interesting, now i'm curious as to why the ceramic capacitor seems to spring to life when it's cooled down?...

(I can't imagine this technique working on an electrolytic)
446  Using Arduino / Microcontrollers / Re: Measuring VCC with an Attiny 85 on: March 08, 2014, 10:37:23 pm
Ugh.  More bad pennies.
Code:
 result = 1125300L / result; // Calculate Vcc (in mV); 1125300 = 1.1*1023*1000
1023 is not correct.  The correct value is 1024.

http://arduino.cc/en/Tutorial/ReadAnalogVoltage


0 - 1023
1 - 1024

The tutirial div's by 1023 ...  if a value of 0 is returned then it's div 1023 not 1024?

Moderator edit: quote trimmed
447  Using Arduino / General Electronics / Re: power leds driver on: March 08, 2014, 05:17:05 pm
Quote
Replace the fet with an npn ...

What's changing to an NPN do for us?  

For us?

....I was talking to fungus, using the n channel fet you need to apply 20 volts or so according to my simulation,  which concurs with  the indestructible's thread...

Switching to a bjt means you can significantly drop the voltage and still power the LED.

I'm not saying you should, I'm intrigued by fungus' s comment, It's not as wasteful as he might think.
448  General Category / General Discussion / parasitic ram explot.. on: March 08, 2014, 09:55:07 am
http://wp.josh.com/2014/03/03/the-mystery-of-the-zombie-ram/

Change the led for a capacitor, avoid eeprom completely?  But is it damaging?
449  Products / Arduino Due / Re: Operating Voltage for components on: March 08, 2014, 09:25:22 am
Gnd/5v (to power the sensor) is fine from the due...

What's not fine is the 5v logic signal, you will need to step it down... zener, voltage divider, regulator before it's fed back to the due.
450  Using Arduino / Project Guidance / Re: calling all experts - need a bit breaduino help... on: March 08, 2014, 09:12:58 am
The two caps on each side of the crystal, you only have 1 correctly seated.

Pages: 1 ... 28 29 [30] 31 32 ... 183