Night rider scanner

[audioguru2]

Nettron,
Eki aren't using 18-pin LM3914s but are probably using the same circuit that you have, except using CMOS instead of your TTL.
A quick check of Kinetics shows that a pendulum doesn't swing exponentially, but more like a sine-wave, since its inertia starts it swinging slowly, the same way that it ends when it runs out of momentum.
What happened to KISS? You sound like an LED salesman. Those LEDs will be coming out of our ears!

 

[Nettron]

Eki aren't using 18-pin LM3914s but are probably using the same circuit that you have, except using CMOS instead of your TTL.

I mean the pendulum concept not the type of IC's used, although cmos would be better when it comes to power consumption, especially if we're talking portability.

What happened to KISS?

Taking a backseat at the moment i guess, im sure it can be refined, perhaps use a sinewave oscillator to drive a 3914('s). Making it more analog rather than digital would be something i would be even more interested in.

You sound like an LED salesman. Those LEDs will be coming out of our ears!

..and for todays special, 2 bags of LEDs for the price of 1 ;D yeah i can imagine a salesman's delight at someone designing a commercial circuit/kit with that many LEDs. Just more eye candy not really necessary
.

 

[Ldanielrosa1]

Have you considered using a microcontroller for this?

 

[audioguru2]

Nettron,
I mentioned CMOS because Eki's kit doesn't appear to have LED current-limiting resistors. CMOS outputs current-limit at about 11mA from a 9V battery.
I agree that linear will look better than logic, because the LM3914 "blends" between adjacent outputs, while logic will go: jerk, jerk, jerk, etc.

Ldanielrosa,
Microcontroller use also is not very original. I can purchase this circuit from my local car-accessory store and have a choice of LED colours. The product has a microcontroller chip under a blob of black epoxy, and the LEDs are surface-mount. It is supposed to make your car appear to have an expensive (and noisy) security system.
Cell-phone covers also have many blinking LEDs.

 

[MP1]

I would tend to agree with LDanielRosa. A microprocessor would be a good way to go. As far as this not being original: Obviously a statement from one who does not program. That would be like saying that there are a lot of op amp circuits, so using one in a new design is not original. The code for a microprocessor will give you complete control of the LEDs in any sequence, pattern, brightness, etc. The program can be as original as you need for it to be - because you are writing it.

MP

 

[Nettron]

A microprocessor would be a good way to go. As far as this not being original: Obviously a statement from one who does not program

I assume by "microprocessor" we mean a microcontroller, yes ive seen that suggested on other forums. A controller such as the PIC can simulate in software just about any logic circuit. I agree this would be a good option if the IC count and "wiring" become too great, but like MP mentioned thats assuming one is comfortable with programming.

This has somewhat jogged my memory ( excuse the coming pun) ,managed to dig up an old schemy of a circuit i once used for proramming SRAM memory IC's. Its an option to using a micro and for programming eliterates, its programmed one bit at a time via a non-encoded keypad.


http://www.geocities.com/nettron1000/2816SRAM.html

Only drawback is that the info will be lost when power is disconnected. A way around this problem would be to use EEPROM's.

 

[Nettron]

A way around this problem would be to use EEPROM's.

Ooops, meant to say non-volitile EEPROM's.

 

[MP1]

Micros have non-volatile built in. ;D

MP

 

[Nettron]

Too bad thay dont have English built-in too ;D, kidding!

 

[ante1]

Hi All,

I don

View attachment 35352

 

[ante1]

And here is the other one.

View attachment 35353

 

[Nettron]

Excellent Ante, a keeper , thanx.

 

[electrodoc2]

http://www.designnotes.com/CIRCUITS/ledflash.htm

this does 10 leds left to right to get a fading effect simply modify the led driver like this link shows.

View attachment 35366