Welcome to fireflyprops.net. Click here to register

The Lassetter

Episode 11 - Trash

Re: The Lassetter

Postby propmaster2000 » Tue Jan 03, 2017 3:44 am

Hi Kurtyboy,

Can you be more specific with the blink/fade pattern of the amber LEDs?
What are you looking to have them do....?
Since LEDs are quicker to respond to power, it is more of a challenge to make them fade like incandescent lights.

.
propmaster2000
Blue Hand guy
 
Posts: 78
Joined: Sat May 23, 2009 12:02 am
Location: So.Cal.

Re: The Lassetter

Postby Kurtyboy » Tue Jan 03, 2017 3:49 am

Just want them to fade out like they do on the original prop, rather than turn off. Speed of fade would be governed by capacitor size.

I just don't know where to put them in the circuit as no matter where I try they make no difference.

propmaster2000 wrote:Hi Kurtyboy,

Can you be more specific with the blink/fade pattern of the amber LEDs?
What are you looking to have them do....?
Since LEDs are quicker to respond to power, it is more of a challenge to make them fade like incandescent lights.

.
User avatar
Kurtyboy
Independent Soldier
 
Posts: 199
Joined: Fri May 22, 2009 7:34 pm

Re: The Lassetter

Postby propmaster2000 » Tue Jan 03, 2017 6:27 am

I see from your videos that you are on the right track.
Are the three amber LEDs tied together from the same flashing clock circuit?
Since they all get power from the same source and fade at the same time, then
only one fade circuit is needed.
If you are driving the three fading LEDs from the same clock source, then you may need
to use a TRANSISTOR to provide the pulsing power to the leds and put a single capacitor on the BASE
of the transistor.
That way when the BASE of the transistor gets a signal to turn it on, it will allow the transistor to conduct powering the leds.

When the clock signal is removed from the BASE, the capacitor will discharge it's voltage slowly thru the base.
The TRANSISTOR only needs a small voltage to turn on, so a small value cap. could be used to slowly decrease it's voltage. You may need to use a resistor as well to slow the discharge.
You would then put the three push buttons on each of the led's.


.
propmaster2000
Blue Hand guy
 
Posts: 78
Joined: Sat May 23, 2009 12:02 am
Location: So.Cal.

Re: The Lassetter

Postby pennausamike » Tue Jan 03, 2017 6:40 am

Kurtyboy wrote:I have zero knowledge or experience of electronics so will have to use some off the shelf circuits and sacrifice some accuracy,
but the main interface is my own work (with thanks to Darth Chromer for his handy tips).
I'm trying to figure out where to put capacitor(s) and what kind, in order to get the yellow LEDs to fade out quickly rather than turn off.


propmaster2000 wrote:I see from your videos that you are on the right track.


Etc, Etc.

Thank goodness someone who knows something responded!
I hated to ignore your posts, but beyond a "Good Job", I haven't anything to offer.

Anyway good luck and continued success,
Mike
User avatar
pennausamike
Browncoat
 
Posts: 2006
Joined: Mon May 25, 2009 1:21 am
Location: Pennsylvania, USA

Re: The Lassetter

Postby Kurtyboy » Tue Jan 03, 2017 2:51 pm

Ah yes, TRANSISTOR! That's the thing with three legs. I'll look into that thanks :)

Here are the videos. For some reason I couldn't get the tags to work.
https://youtu.be/cUdAHvmwf5M

https://youtu.be/Dwp0Jx_1Y6o
User avatar
Kurtyboy
Independent Soldier
 
Posts: 199
Joined: Fri May 22, 2009 7:34 pm

Re: The Lassetter

Postby Kurtyboy » Tue Jan 03, 2017 3:13 pm

Anyone know if the head of the flash light swivels on the prop or if it's fixed in the up position?
User avatar
Kurtyboy
Independent Soldier
 
Posts: 199
Joined: Fri May 22, 2009 7:34 pm

Re: The Lassetter

Postby propmaster2000 » Tue Jan 03, 2017 3:37 pm

Hi Kurtyboy,

It is fixed in this position:
Image

Also, here is a quick sketch of a circuit that could be used to make the LEDs fade.

Since I don't know what you are using for the clock, I am showing a 555-IC (an LM3909
will work as well).
Using the POSITIVE signal from the IC it goes through a 10k resistor and then
through a small signal diode ( the diode keeps the capacitor from discharging back
through the 555 - clock circuit ). That voltage charges the capacitor and then goes
through a small value resistor (1k - this resistor may not be needed).
This small positive voltage will turn on the small signal (TO92-2N4401/2N2222)
NPN TRANSISTOR (allowing it to conduct like a switch) there by turning on the
three AMBER LEDs. I put small value resistors at each LED is to limit there current.
I don't know what the POSITIVE voltage is so I am being safe.
When the clock signal goes negative, the remain voltage in the capacitor discharges slowly
through the BASE of the transistor until the next pulse.
If it is discharging to slow (takes too long), then change the value of the cap. to a smaller value.
I am showing a 47mf (10mf to 25mf).
Put your push button switches in series to turn them on and off individually.

(here is my diagram)

Image

.
propmaster2000
Blue Hand guy
 
Posts: 78
Joined: Sat May 23, 2009 12:02 am
Location: So.Cal.

Re: The Lassetter

Postby Kurtyboy » Tue Jan 03, 2017 4:08 pm

Thanks for that. I've tried adapting my circuit diagram using your addition. The switches are not shown as it gets too complicated for me.
Image

Image

Do either look correct? What size of NPN would I need for this voltage and resistance?

Thank you!
User avatar
Kurtyboy
Independent Soldier
 
Posts: 199
Joined: Fri May 22, 2009 7:34 pm

Re: The Lassetter

Postby Kurtyboy » Tue Jan 03, 2017 4:52 pm

Anyone know where the on/off switch is on the Lassiter? I can see the trigger switch for the emitters and the switch on the back of the grip is presumably for the sight rod LED, but I can't see what turns the rear screen/counter on.

https://youtu.be/sLwLhQBO4pg?t=118
User avatar
Kurtyboy
Independent Soldier
 
Posts: 199
Joined: Fri May 22, 2009 7:34 pm

Re: The Lassetter

Postby propmaster2000 » Tue Jan 03, 2017 5:03 pm

Kurtyboy wrote:Thanks for that. I've tried adapting my circuit diagram using your addition. The switches are not shown as it gets too complicated for me.
Image

Image

Do either look correct? What size of NPN would I need for this voltage and resistance?

Thank you!


Hi Kurtyboy,
Neither of your drawings above show positive voltage to the LEDs and your 47uf is blocking the negative side.

I see you have the clock signal going to a resistor, that is good, but you need the capacitor to slow the discharge for the slow OFF signal.
I added the 1N914 to the circuit so that the capacitor does not discharge back through the clock circuit. Since you are using a 9V battery to drive the LEDs, I would recommend a resistor value of 470 ohm instead of 220. (I did not know what your battery source was).
Added note:
You also may need a resistor 2.2K between the capacitor connection and the base of the NPN,
and experiment with a smaller value of CAP. maybe a 10uf.
I changed the 47uf to a (25uf - oops!) 22uf in my revision (sorry about that) :) .

Image

.
Last edited by propmaster2000 on Tue Jan 03, 2017 6:05 pm, edited 2 times in total.
propmaster2000
Blue Hand guy
 
Posts: 78
Joined: Sat May 23, 2009 12:02 am
Location: So.Cal.

PreviousNext

Return to Trash

Who is online

Users browsing this forum: No registered users and 1 guest

cron