LED Flasher Relay

[peterbaron]

Yeah, wine cellar is already flooded

[GoldOxide_imp]

Sorry Popgun - wasn't supposed to go that far.

[Lord Popgun]

Dang, now I’m full of gas? Good thing I live alone.

Its ok Gold, I only burned up part of the harness and popped one fuse. Ok, not really, just the fuse. Gotta get a replacement for the spare now.

Actually wasn’t that bad and I have the pics ready to go. Will write up the stuff and post the pics later. Still have to put my headlight back in the bucket. Couple of screws—done.

[Lord Popgun]

For those who do not know how to interpret signals on an oscilloscope I’ll try to give a small explanation.

O-scopes display a voltage that takes place over time. The could be constant DC. Could be AC like in your house. Could be waveforms of all types. In our case here, we will see square waves.

The screen is divided into a grid pattern with horizontal and vertical lines. These spaces between the lines are known as divisions. Each of the divisions has ‘tic’ marks. If you start at a line and count tic marks to the next line you will count 5. The value of the divisions, and thus each tic, will depend on scope settings that the user selects.

The trace on a scope can be positioned on any horizontal line. Or anywhere for that matter. Usually the center line is used to put the trace on with no signal, or 0v. And that is what I did for the pics.

When looking at a signal you must select a voltage range. For instance, 10v. Or actually 10v per division. Voltage is displayed going up and/or down. So if you start at one horizontal line, going to the next line is equal to 10v. Each tic would be equal to 2v as 5x2=10. So 12v will show as one division plus 1 tic. Other voltage levels can be selected.

Time goes from left to right. You select a time base that will show the signal as you want. So, for instance, 5ms (milliseconds) So from one vertical line to the next would take 5ms. Each tic would be 1ms. A pulse that is 1 division and one tic would be 6ms.

In the pics the pulse trains look pretty much the same until you see the time base is different, thus the pulse widths and repetition rates are different. I will point that out with the pics in a following post as I don’t know how long a post can be.
Test equipment: Tektronix TBS 1052 dual trace 50MHz digital scope.

Test setup: Scope probe connected to the left turn signal orange wire in headlight shell. Probe ground lead connected to the ground plate in the left turn signal (easy to get to and the lens was already off).

Bike-battery tender disconnected. Ignition key on, bike not running.

Scope set to 10v per div and 5ms per div.

[url=https://app.photobucket.com/u/everettmclendon/a/a8b5b03b-ad65-49a1-a3d0-f45df1fc2c20/p/75178ebe-275d-493f-aea0-37df9fe25eff]

First, The settings shown should be /division not /cm I had centimeters on the brain last night.

In the pic the running lights are on. The picture shows that they are light by a pulsed 12vdc. The pulses show the voltage is on for 2ms and off for 4ms. Since the voltage is not a constant 12v they are dimmer than they would if fed a constant 12v.

[url=https://app.photobucket.com/u/everettmclendon/a/a8b5b03b-ad65-49a1-a3d0-f45df1fc2c20/p/36df8cf5-894b-45b6-9822-c698cc4dee01]

The above pic is with the left turn signal selected.
The scope is set to 10v/div and 500ms/div

The turn signal light flashes by the voltage turning on and off (obviously) It is on for ~400ms and off for ~300ms or on about .4sec and off for .3 sec.

You can see the pulses are 12v as they are 1 division high plus 1 tic. That is 10+2=12

Any mistakes blame PB

[GoldOxide_imp]

Looks great L.Popgun. I also like the slip up into metric (i.e. cm). Did you work for NASA? Nevertheless, encouraging.

The switching is very concise and clean, but it is also a slow uncomplicated cycle too.

So, when Forum members play with LED modifications, is there a chance their subassemblies:

a) Don't like the switching 12V line? Maybe they were expecting something else like a constant 12V and ground feed, and a pulse train to trigger their circuit? (I don't know because I haven't looked at any LED products).

b) The source current is not enough for the switching LED subassembly? If so, I would expect on their set-up your voltage pulse train to be distorted and/or drawn down to a lower level.

[Cormanus]

Thanks for a very clear explanation Lord Popgun. Because I know so little about electrics, I’m going to ask what may be a very silly question. Why not feed the running lights a constant lower voltage to produce a less intense light?

[Lord Popgun]

Not sure. I would guess that doing it this way generates very little heat, maybe less costly design. Something with a dropping resister or voltage regulation circuit is going to get hot, or at least get hotter, and have the problems you have with that—shorter life, more complex, more costly, etc.

[peterbaron]

For those who do not know how to interpret signals on an oscilloscope I’ll try to give a small explanation.

O-scopes display a voltage that takes place over time. The could be constant DC. Could be AC like in your house. Could be waveforms of all types. In our case here, we will see square waves.

The screen is divided into a grid pattern with horizontal and vertical lines. These spaces between the lines are known as divisions. Each of the divisions has ‘tic’ marks. If you start at a line and count tic marks to the next line you will count 5. The value of the divisions, and thus each tic, will depend on scope settings that the user selects.

The trace on a scope can be positioned on any horizontal line. Or anywhere for that matter. Usually the center line is used to put the trace on with no signal, or 0v. And that is what I did for the pics.

When looking at a signal you must select a voltage range. For instance, 10v. Or actually 10v per division. Voltage is displayed going up and/or down. So if you start at one horizontal line, going to the next line is equal to 10v. Each tic would be equal to 2v as 5x2=10. So 12v will show as one division plus 1 tic. Other voltage levels can be selected.

Time goes from left to right. You select a time base that will show the signal as you want. So, for instance, 5ms (milliseconds) So from one vertical line to the next would take 5ms. Each tic would be 1ms. A pulse that is 1 division and one tic would be 6ms.

In the pics the pulse trains look pretty much the same until you see the time base is different, thus the pulse widths and repetition rates are different. I will point that out with the pics in a following post as I don’t know how long a post can be.
Test equipment: Tektronix TBS 1052 dual trace 50MHz digital scope.

Test setup: Scope probe connected to the left turn signal orange wire in headlight shell. Probe ground lead connected to the ground plate in the left turn signal (easy to get to and the lens was already off).

Bike-battery tender disconnected. Ignition key on, bike not running.

Scope set to 10v per div and 5ms per div.

[url=https://app.photobucket.com/u/everettmclendon/a/a8b5b03b-ad65-49a1-a3d0-f45df1fc2c20/p/75178ebe-275d-493f-aea0-37df9fe25eff]

First, The settings shown should be /division not /cm I had centimeters on the brain last night.

In the pic the running lights are on. The picture shows that they are light by a pulsed 12vdc. The pulses show the voltage is on for 2ms and off for 4ms. Since the voltage is not a constant 12v they are dimmer than they would if fed a constant 12v.

[url=https://app.photobucket.com/u/everettmclendon/a/a8b5b03b-ad65-49a1-a3d0-f45df1fc2c20/p/36df8cf5-894b-45b6-9822-c698cc4dee01]

The above pic is with the left turn signal selected.
The scope is set to 10v/div and 500ms/div

The turn signal light flashes by the voltage turning on and off (obviously) It is on for ~400ms and off for ~300ms or on about .4sec and off for .3 sec.

You can see the pulses are 12v as they are 1 division high plus 1 tic. That is 10+2=12

Any mistakes blame PB

Yeah, right....
I have the newest BT DSO with an instant digital printer that can be taken with me for a spin.....no 5 mile extension cord needed for cruising a neighbourhood while testing motorcycle turn signals.....

[GoldOxide_imp]

There is a power savings advantage to pulsing the light load versus full on 12V and then dumping some on a dummy load - yes.

[Lord Popgun]

Now you confuse people with your wrong voltages and pulse widths. (PB and I are messing with each other here, just so people know).

PB- Tektronix keeps sending me email to buy one of those 10-30 thousand dollar scopes. Like I need one. They even offer to send one to try out. Nope. Mine was about $500 and is good enough for most home stuff. I don’t do any RF at home so 50Mhz is good enough too.

Wouldn’t mind a spectrum analyser but they sure don’t give those away.