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Luft kühl
Samba Member
Joined: January 21, 2009
Posts: 1178
Location: Allentown, PA
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 Posted: Thu Dec 28, 2017 6:44 pm Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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| bluebus86 wrote: |
10 milliseconds is 1/100th of a second
new math?
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10 milliseconds is 10 one millionths of one second
Same old math. Its a shame that you never learned very much of it.
Last edited by Luft kühl on Thu Dec 28, 2017 6:53 pm; edited 2 times in total |
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kangaboy
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Joined: August 28, 2010
Posts: 1064
Location: St. Louis, Mo
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| Posted: Thu Dec 28, 2017 6:45 pm Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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Wow...if ever we needed an alert to get back on topic, it would be now.
Anyone else have examples of their mechanical switches installed on their cars.
_________________
-74 Standard - "CaliBug" 2084T, MS3X w/FI and Crank Fire
-76 Westy - "Gandalf"
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bluebus86
Banned
Joined: September 02, 2010
Posts: 11075
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| Posted: Thu Dec 28, 2017 8:07 pm Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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| Luft kühl wrote: |
| bluebus86 wrote: |
10 milliseconds is 1/100th of a second
new math?
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10 milliseconds is 10 one millionths of one second
Same old math. Its a shame that you never learned very much of it. |
So you say I never learned much of math???
The below link should set you straight...
https://en.m.wikipedia.org/wiki/Millisecond
A millisecond is 0.001 second, 1/1000th of a second. 10 milliseconds is thus 0.01 or 1/100th of a second.
Kind of like a millimeter is 0.001 meter.
A nano is 1/1,000,000,000
A micro is 1/1,000,000
A milli is 1/1000.
Bug On, class is concluded for today!
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Luft kühl
Samba Member
Joined: January 21, 2009
Posts: 1178
Location: Allentown, PA
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| Posted: Thu Dec 28, 2017 8:30 pm Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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Ok I stand corrected on the millisecond vs microsecond argument. My numbers were for microseconds (solid state relays).
The reaction time for a human would still not make any significant difference weather a relay was used or not.
Can you react in 1/100th of a second ? |
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bluebus86
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Joined: September 02, 2010
Posts: 11075
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| Posted: Thu Dec 28, 2017 11:01 pm Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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| Luft kühl wrote: |
Ok I stand corrected on the millisecond vs microsecond argument. My numbers were for microseconds (solid state relays).
The reaction time for a human would still not make any significant difference weather a relay was used or not.
Can you react in 1/100th of a second ? |
Its not the human reaction time that is the issue, the issue is when the human is first informed of the need to react, at freeway speeds the time frame discussed equates to about a foot of distance. The sooner the human is alerted, the sooner the human can react. how long the human takes to react is a totally different issue.
Would you rather have the car behind you have an inch of room to spare in stopping distance, or be short a 11 inches of stopping distance, and thus smash your rear end?
The time for the brake light to illuminate upon triggering the brake switch is not at all related to a given humans reaction time in the following car. These are completely different issues, but the sooner the human is alerted, the sooner he can react. How long he takes to react is not relevant to this.
Bug On!
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EVfun 
Samba Member
Joined: April 01, 2012
Posts: 5894
Location: Seattle
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| Posted: Thu Dec 28, 2017 11:33 pm Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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| bluebus86 wrote: |
Its not the human reaction time that is the issue, the issue is when the human is first informed of the need to react, at freeway speeds the time frame discussed equates to about a foot of distance. The sooner the human is alerted, the sooner the human can react. how long the human takes to react is a totally different issue.
Would you rather have the car behind you have an inch of room to spare in stopping distance, or be short a 11 inches of stopping distance, and thus smash your rear end?
The time for the brake light to illuminate upon triggering the brake switch is not at all related to a given humans reaction time in the following car. These are completely different issues, but the sooner the human is alerted, the sooner he can react. How long he takes to react is not relevant to this.
Bug On! |
??? An extra foot of distance before the brake light illuminate is one less foot of reaction time for the following driver, whether it is because of the time it takes a relay to close or slow illumination of an incandescent bulb.
However, a pressure brake light switch cannot possibly operate until the pedal free play is taken up, then the piston moved until the bleeder ports are covered, and then enough additional pedal travel to begin to develop pressure in the brake hydraulics. A mechanical brake light switch is often adjusted (on cars using them) so they operate with 1/4 inch or so of pedal travel. Even if the mechanical switch needs a relay to operate the brake lights it may be faster to power them.
For that reason I would not resist a mechanical brake light switch solely because it needed a relay. There is not a lot of room for a switch on a Bug so a small switch that needs help handling the current may be the easiest way to go with a mechanical switch. It was a lot easier for me because the pedals where moved back 10 inches for the Berry Mini-T body. I used a common roller tip industrial microswitch because they tend to be very rugged.
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Fiddlestyx
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Joined: July 08, 2015
Posts: 405
Location: Texas
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| Posted: Fri Dec 29, 2017 8:00 am Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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Let's stop derailing the topic, please.
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bluebus86
Banned
Joined: September 02, 2010
Posts: 11075
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| Posted: Fri Dec 29, 2017 9:19 am Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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| EVfun wrote: |
| bluebus86 wrote: |
Its not the human reaction time that is the issue, the issue is when the human is first informed of the need to react, at freeway speeds the time frame discussed equates to about a foot of distance. The sooner the human is alerted, the sooner the human can react. how long the human takes to react is a totally different issue.
Would you rather have the car behind you have an inch of room to spare in stopping distance, or be short a 11 inches of stopping distance, and thus smash your rear end?
The time for the brake light to illuminate upon triggering the brake switch is not at all related to a given humans reaction time in the following car. These are completely different issues, but the sooner the human is alerted, the sooner he can react. How long he takes to react is not relevant to this.
Bug On! |
??? An extra foot of distance before the brake light illuminate is one less foot of reaction time for the following driver, whether it is because of the time it takes a relay to close or slow illumination of an incandescent bulb.
However, a pressure brake light switch cannot possibly operate until the pedal free play is taken up, then the piston moved until the bleeder ports are covered, and then enough additional pedal travel to begin to develop pressure in the brake hydraulics. A mechanical brake light switch is often adjusted (on cars using them) so they operate with 1/4 inch or so of pedal travel. Even if the mechanical switch needs a relay to operate the brake lights it may be faster to power them.
For that reason I would not resist a mechanical brake light switch solely because it needed a relay. There is not a lot of room for a switch on a Bug so a small switch that needs help handling the current may be the easiest way to go with a mechanical switch. It was a lot easier for me because the pedals where moved back 10 inches for the Berry Mini-T body. I used a common roller tip industrial microswitch because they tend to be very rugged. |
Granted, that above is true, but if a relay is not needed, you gain a foot of extra stopping distance, elimination of a relay is a good thing if it can be done. I have a 914 car, brake light switch on the pedal arm, no relay. (factory set up) the switch can handle the current load with no need for a relay. My point has been that if a relay is added, there is an additional time delay, equivalent to about a foot of travel at freeway speeds.
Thus if you design a switch system, if you can do it without a relay, you can gain a foot of margin over a system with a relay. So use a switch that can handle the current verse a switch that needs a relay.
Bug On, Dont Be Rearended!
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GearHeadKeith
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Joined: January 14, 2003
Posts: 112
Location: Detroit, MI
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| Posted: Sat Dec 30, 2017 8:54 am Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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Trying to get this back in topic, my concept is to add an electromechanical switch in parallel with the OE master cylinder switches. With any of the 3 switches in this circuit (2 in the MC, my switch at the pedal) are closed, the brake lights are activated. I have mine configured that the switch at the pedal closes the circuit with about 1" of pedal pad movement.
It is very similar to switch by kangaboy. However, I think my bracket and switch are well integrated into the vehicle from a visual, mechanical attachment, and wiring perspective. It is totally hidden from view, located behind the accelerator pedal in the dead zone between pedal travel and the floorpan. Here is a picture of a prototype (not the finished product). Please note, I pulled the accelerator pedal rearward in this picture to better show the brake light switch:
My car requires 20lbs of pedal force on the brake pedal pad before the OE switch activates the brake lights. On a light stop, my brake lights never turned on as I did not meet this force threshold. I replaced the MC switches several times w/o improvement. My pedal-activated switch turns them on immediately.
I should have this ready for sale by the end January. I'll update this post when it is ready.
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Keith Gilbert - DdK
1971 Super Beetle sedan, Shantung yellow with black interior. Cosmetically unrestored with over 366k miles.
1776cc: 9.2:1 compression, dual Weber 40DCN on Deano intakes, Primo Petrucci 40mm/36mm round-port heads, Crower VW284F cam, Kymco 1.5" exhaust
SSC trans with 3.78/2.25/1.48/1.04 & 4.12 Gleason R&P, Type IV output flanges, Berg Shifter
Topline front struts/springs/sway bar, Sway-a-Way rear bar, 4-wheel disc brakes
Owned since 1994: 3rd owner since new! |
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bluebus86
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Joined: September 02, 2010
Posts: 11075
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| Posted: Sat Dec 30, 2017 11:06 am Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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pretty slick set up. what current capacity is the switch you are using? it would be nice if it can handle the higher current 6 volt system requirements, and even additional lights such as add on third mount stop lights. Of course led bulbs can overcome current limitations, but not everyone may choose the led upgrade.
this should be a great safety improvement. dingbat unattentive tailgaters need all the warning possible. I have had three cars totalled by rear end collisions at traffic signals, big time injuries.
this is good news.
Bug On, Stop Safe!
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EVfun
Samba Member
Joined: April 01, 2012
Posts: 5894
Location: Seattle
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| Posted: Sat Dec 30, 2017 12:07 pm Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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| GearHeadKeith wrote: |
It is very similar to switch by kangaboy. However, I think my bracket and switch are well integrated into the vehicle from a visual, mechanical attachment, and wiring perspective. It is totally hidden from view, located behind the accelerator pedal in the dead zone between pedal travel and the floorpan. Here is a picture of a prototype (not the finished product). Please note, I pulled the accelerator pedal rearward in this picture to better show the brake light switch:
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What is the current rating of that switch? I found many of the smaller industrial style microswitches don't have a very high current rating. That is why I'm using the next size larger with the screw terminals. Few microswitches seem to have an incandescent lamp load rating (may also be called tungsten load, and could be combined with the capacitive load rating.) Here is a brief bit about relays and light bulbs, the same idea applies to switch contacts. Usually the derating for incandescent loads allow the switch to handle around 1/4 the rated current. My microswitch is rated for 15 amps resistive load. I estimate that will safely operate 42 watts of 12 volt bulbs. Here is a little bit from the switch maker NKK.
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| Wildthings wrote: |
| As a general rule, cheap parts are the most expensive parts you can buy. |
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bluebus86
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GearHeadKeith
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Joined: January 14, 2003
Posts: 112
Location: Detroit, MI
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| Posted: Sat Dec 30, 2017 1:58 pm Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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The switch is rated for 5 amps at 30VDC. Since the OE 1156 bulbs are 26.9 watts and assuming 12.8 VDC, the amperage per bulb is 2.1 amp. 2.1 amp x 2 bulbs = 4.1 amp.
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Keith Gilbert - DdK
1971 Super Beetle sedan, Shantung yellow with black interior. Cosmetically unrestored with over 366k miles.
1776cc: 9.2:1 compression, dual Weber 40DCN on Deano intakes, Primo Petrucci 40mm/36mm round-port heads, Crower VW284F cam, Kymco 1.5" exhaust
SSC trans with 3.78/2.25/1.48/1.04 & 4.12 Gleason R&P, Type IV output flanges, Berg Shifter
Topline front struts/springs/sway bar, Sway-a-Way rear bar, 4-wheel disc brakes
Owned since 1994: 3rd owner since new!
Last edited by GearHeadKeith on Mon Jan 15, 2018 7:52 pm; edited 1 time in total |
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sleeper bird
Samba Member
Joined: August 27, 2017
Posts: 121
Location: Louisiana
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| Posted: Sat Dec 30, 2017 5:37 pm Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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| any idea about what it would cost?Good idea by the way |
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EVfun
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Joined: April 01, 2012
Posts: 5894
Location: Seattle
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| Posted: Sat Dec 30, 2017 5:57 pm Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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The current rating of a switch does not continue to to go up as the voltage goes down.
When the lights first get power they will attempt to draw about 25 amps and your switch is rated for 5. Now with any luck there are enough just o.k. connections that there is some extra reistance in the wiring to limit the inrush current. It will almost certainly briefly exceed 5 amps. Since my wiring is all new I'm actually concerned about the 15 amp rating of my switch.
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| Wildthings wrote: |
| As a general rule, cheap parts are the most expensive parts you can buy. |
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bluebus86
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Joined: September 02, 2010
Posts: 11075
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| Posted: Sat Dec 30, 2017 8:53 pm Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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| GearHeadKeith wrote: |
The switch is rated for 5 amps at 30VDC. At 12VDC, I calculate that it is OK for 12.5 amps. Similarly, 6VDC equates to 25 amps. It uses 0.187" x 0.032" quick-disconnect terminals
Since the OE 1156 bulbs are 26.9 watts and assuming 12.8 VDC, the amperage per bulb is 2.1 amp. 2.1 amp x 2 bulbs = 4.1 amp. Plenty of safety margin. |
A lower voltage should not increase the current rating of the switch you may need a higher rated switch as the bulbs consume 4.1 amps as you calculated, that means your using just over 80% of the switches capacity. add to that the derating needed for the bulbs per the link you posted (Very handy by the way!) and your switch is not going to be happy.
LED bulbs should allow you to use this switch however. But note, if you sell this switch to folks with combined stop and turn signal bulbs as the pre 62 Bugs use, if LEDs are used, a resistor need be added to allow the flasher relay to function correctly.
anyhow, with a 5 amp switch, you will want to specify it to be used with led bulbs. note some folks also use higher watt incandecent bulbs for stop lights, so that may exceed the 4.1 amps you have calculated. some folks also have added high mount stop lights (I have) which could double the current.
But use of LEDs should solve current issues with this switch, and LEDs are safer anyway, faster response time.
You should specify this upgrade must use LEDs for switch life, else you may have premature failures.
Id recommend you sell the led bulbs as part of the package, both the switch and the LEDs with give the fastest response of lights to braking, and allow use of this switch. just note pre 62 Bugs use the combined turn/brake bulb, and conversion to LED in these early cars will require a resistor to make the flasher work at the correct speed.
Bug On!
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TX-73
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Joined: January 04, 2013
Posts: 1133
Location: Texas
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| Posted: Sun Dec 31, 2017 10:45 am Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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IMO anything you can do to brighten and/or reduce activation delay is great, kudos to OP for having the initiative to try to make an improvement.
Small additional comment, you don't necessarily need to add resistors if you use the correct relay. I have LED inside and out on the bug, headlights to taillights to interior. I first had installed a CF13 digital relay but couldn't figure out why turns just didn't work right. Ashman helped me out on this - he explained that the bug setup needs an EP35 relay not a CF13. The pos and neg leads on the CF 13 need to be reversed for the relay to function is the short story; the EP35 relay is already set up in this manner. I installed the EP35 and everything works great.
A small thing but it tripped me up, BIG thanks to Ashman.
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My 1973 Standard Beetle Build SOLD
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mondshine
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Joined: October 27, 2006
Posts: 2798
Location: The World's Motor Capital
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| Posted: Sun Dec 31, 2017 11:32 am Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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The switch installed by Keith looks like a nice way to accomplish this.
I purchased the "Smart Brake Light Switch" a few years ago and it is a great upgrade. It is a very well made, but complex mechanism, and it was a little expensive (probably why they are NLA).
My '74 Thing has front disc brakes, and I noticed that the brakes would begin to take hold before actuating the stock hydraulic brake light switches.
I like the idea of giving the driver behind me as much time as possible to react, so having my brake lights illuminate as soon as I touch the pedal is a good thing.
The auxiliary brake light switch had no effect on the function of the stock brake warning light.
An addition benefit is that since my Thing has cruise control, a light tap on the brake pedal will disengage the cruise without actually slowing the car down (just like on a real car  ).
On my '74 Thing, the switch (SPST NC) is wired like this:
Just for laughs, here is the video for the (NLA) "Smart Brake Light Switch".
Link
Notice the complexity of the whole apparatus!
A feature you might considering incorporating into your design is the range of adjustability of the switching point (for car-to-car variations) and using a waterproof (or harsh environment) rated microswitch.
Best of luck with your project, Mondshine
Last edited by mondshine on Sun Dec 31, 2017 3:36 pm; edited 1 time in total |
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GearHeadKeith
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Joined: January 14, 2003
Posts: 112
Location: Detroit, MI
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| Posted: Sun Dec 31, 2017 2:58 pm Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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Sleeper_bird: Thanks for the kudos! The intent of this post was direct traffic to a survey (https://www.surveymonkey.com/r/LF26FK8), to collect data so I can judge the market demand for this switch kit and see if there is a business case, as there are many factors involved. I do not have a final price set.
EVFun & bluebus86: thanks for the feedback: I really appreciate it. I have been working directly with the business development group at this particular switch manufacturer. I will check with them this next week on the durability of this switch under this particular operating condition.
Nondshine: thanks for the info on the “Smart Brake Light Switch”! It is a similar concept with a very complicated execution!
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Keith Gilbert - DdK
1971 Super Beetle sedan, Shantung yellow with black interior. Cosmetically unrestored with over 366k miles.
1776cc: 9.2:1 compression, dual Weber 40DCN on Deano intakes, Primo Petrucci 40mm/36mm round-port heads, Crower VW284F cam, Kymco 1.5" exhaust
SSC trans with 3.78/2.25/1.48/1.04 & 4.12 Gleason R&P, Type IV output flanges, Berg Shifter
Topline front struts/springs/sway bar, Sway-a-Way rear bar, 4-wheel disc brakes
Owned since 1994: 3rd owner since new!
Last edited by GearHeadKeith on Mon Jan 15, 2018 1:47 pm; edited 1 time in total |
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sleeper bird
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Joined: August 27, 2017
Posts: 121
Location: Louisiana
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| Posted: Sun Dec 31, 2017 4:14 pm Post subject: Re: Brake Pedal Activated Brake Light Switch - Interest Survey |
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| i completed the survey |
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