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FLASHER /BEEPER...siiigh

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kimbear

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Ok guys, laff if you must, but this 'ol buggar need some analogue help
My car makes ZERO sound when the turn signals are flashing, the lights are not really noticeable, and the turn signal doesn't always turn off when I'm finishing a turn. Yup...I'm one of THOSE people who sometimes drives down the street with my turn signals flashing.
Now Ive disassembled my steering column, and I have found the ground, as well as both left and right turn signal switch outputs.
SOOOOO...what I would like is a really basic analogue circuit that beeps, and flashes a ultrabrite led in my face when the turn signals are on for ohhh...lets say, longer than 10 seconds. Ill mount it on my steering column in my line of vision, to let me know.
So whatcha think???...I was thinking of something like a 556 missing pulse detector (thinking back to good old Forest J Mims) that is happily pulsing away, interrupted by the input from the signal switch....that sorta thang
Thanks in advance for helping.
 
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Les Jones

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I would have thought specifying "analogue" would exclude the use of the 555 or 556 IC . To be purely analogue I would think you would allow the use of op amps (Provided they were not allowed to saturate.) but not comparators.

Les.
 

MikeMl

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What voltage is on both the turn signal switch outputs with the switch centered? (WRT Gnd)

What voltage is on both the turn signal switch outputs with the switch in the right turn position?

What voltage is on both the turn signal switch outputs with the switch in the left turn position?

Would it be easier to interface to the turn lamps?

How about installing a clunky old relay (and two diodes) under the dash? The relay click should remind you that the flashers are on ( or are you deaf, like me;))?
 
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AnalogKid

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This can be done with one 555: 10 second R-C time delay on the Reset pin, standard 50% duty cycle oscillator, direct drive to the LED and beeper.

BUT, here is the ***RIGHT*** way:

Two crystal controlled sinewave oscillators, a Colpitts running at 100.000 kHz, and a Pierce running at 100.001 kHz. These feed the two inputs of a doubly-balanced mixer. The output is a 1 Hz sinewave that drives the LED. Next to the LED is a cadmium-sulphide cell. Current through the cell enables a 400 Hz Wein Bridge oscillator that drives a speaker.

You're welcome.

ak

OR, a CD4093 quad NAND, or any other gate package with hysteresis, making a gated oscillator that drives a 2N7002 that drives the LED and beeper.

OR, since this is automotive and I'm not a huge 555 fan, all of that with one ULN2003. Now we're talkin...
 

AnalogKid

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If the current through the steering column switches is pulsing (ground path for the turn signal lights), then the CD4093 approach can do this. If it is steady (control signal for a flashing device), then one 555 should do it.

ak
 

cowboybob

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Pretty sure most turn signal lights are grounded and fed a "positive" DC from the flasher relay.

And this doesn't exactly fit your design:
what I would like is a really basic analogue circuit that beeps, and flashes a ultrabrite led in my face when the turn signals are on for ohhh...lets say, longer than 10 seconds. Ill mount it on my steering column in my line of vision, to let me know.
(My emphasis.)

But, how about just find the "blinker" relay (there's got to be one somewhere, and generally close to the steering column area) and splice a line from its output to a simple piezo/LED circuit:
upload_2016-12-2_8-58-43.pnghttp://www.ebay.tv/sch/i.html?_sop=...rand=RadioShack&_dcat=14964&_nkw=piezo+buzzer
 

AnalogKid

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But wait, there's more. As a starting point, here is an all-digital (that just sucks, man) solution from last December on another forum. Rather than an R-C delay or missing pulse detector, it counts turn signal flashes and beeps on every tenth one. With one additional diode that can be changed to latching on after x signal flashes. Add the LED and its series resistor in parallel with the beeper.

ak
TurnSignalBuzzer-1-c.gif
 

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AnalogKid

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There are about six different ways to do this. Really need to know the true nature of the signals/wires available to the circuit.

ak
 

kimbear

Member
Ok, ok, ok.....I keep forgetting you guys are all geniuses, and my attempt at asking of a "Analogue" circuit may have been taken a bit too literally...which is entirely my fault.

I meant no microprocessors....555's, 741's 4017's...etc...are what I meant.

Taking the dash apart to get to the signal light is a pain in the ass....I can easily access the turn signal switches in the steering column tho.
The relays that provide the flashing are all under the hood...that's why I cant hear em...and yes, my hearing isn't what it used to be (you can thank the whole Disco era for that...DAMN YOU BEE GEES!!)
12v dc is available at the turn signal switch, which is simply a on/off/on arrangement with the center position as off. Using steering diodes, I can combine the 2 into 1 =12vdc signal when either one is activated.
The beeper isn't the problem, I have a tiny 12v Sonalert for that.
I don't want the signal for a short time, when I'm changing lanes, or just doing a turn, I want it to annunciate only when left on an extended period of time.

Sometimes we lower forms of intelligence have a harder time communicating with higher forms.
Thanks for the response so far guys, I do appreciate the help.

PS- ummm ...err...the flashing LED isn't a problem either, I can do that part myself.
 

DerStrom8

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I think you all are over-complicating this.

kimbear , setting a timer before triggering an alarm is probably not a very good way to go about this. What if you're in line at a traffic light? Your turn signal is probably going to be on for a good long while before the traffic starts moving, and you don't want this thing blaring and flashing in your face almost the entire time.

I suggest using a simple circuit that makes the turn signal audible, whether it be a beep or a click. But not an alarm -- That would get annoying really fast. Most cars nowadays have loud relays that allow the driver to hear when their signal is on. I don't think you'd really need any ICs for that. Just connect a big ol' relay that somehow taps into the current turn signal circuit so that it's activated every time your light flashes. If you want you can connect a light to the other side of the relay too so it flashes in time with your turn signal.

This isn't a final solution, but hopefully it serves as a good jumping-off point.

Matt
 

Les Jones

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I think this should do what you want.
Delay_flash.jpg


You will probably have to adjust the value of the 220K resistor as electrolytic capacitors have a very wide tolerance.

I am inclined to agree with DerStrom8 that just a noisy relay would be a better solution.

Les.
 

AnalogKid

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I agree with DerStrom - something that is rigidly timer-based fits only a narrow range of driving conditions. This circuit is more of a gentle periodic reminder than a timeout alarm. I haven't given up on the counter-based idea, but a gated 555 is pretty simple, especially when the available input signals are so limited.

D1-D2-Q1 form a NOR gate that enables the 555 oscillator whenever either turn signal connection is grounded. R1 secures the Q1 gate when both inputs are open. D3 makes the 555 wildly asymmetrical - 0.5 s on, 10 s off. While the two timing resistors do interact, it's not by much; adjust R3 for ON time, R4 for OFF time.

ak
TurnSignalBuzzer-3-c.gif
 

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kimbear

Member
Analogue Kid
Doth Pin 5 get connected to anything?
Thank you for the circuit

I agree with DerStrom - something that is rigidly timer-based fits only a narrow range of driving conditions. This circuit is more of a gentle periodic reminder than a timeout alarm. I haven't given up on the counter-based idea, but a gated 555 is pretty simple, especially when the available input signals are so limited.

D1-D2-Q1 form a NOR gate that enables the 555 oscillator whenever either turn signal connection is grounded. R1 secures the Q1 gate when both inputs are open. D3 makes the 555 wildly asymmetrical - 0.5 s on, 10 s off. While the two timing resistors do interact, it's not by much; adjust R3 for ON time, R4 for OFF time.

ak
View attachment 102814
 

AnalogKid

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Doth Pin 5 get connected to anything?
Not in my world. That modulation input is a fairly low input impedance point, and a little induced noise on the internal resistor divider stack isn't going to affect the circuit operation noticeably. The universe has only so much capacitance to go around; save your 0.00000001 F for something else.

ak

Question: When the turn signal switch is grounding one wire, what voltage is on the other wire with something like 10K to GND? Depending on how the car is wired, it might be pulsing at the signal rate. This could be used for the counter circuit.
 

kimbear

Member
Not in my world. That modulation input is a fairly low input impedance point, and a little induced noise on the internal resistor divider stack isn't going to affect the circuit operation noticeably. The universe has only so much capacitance to go around; save your 0.00000001 F for something else.

ak

Question: When the turn signal switch is grounding one wire, what voltage is on the other wire with something like 10K to GND? Depending on how the car is wired, it might be pulsing at the signal rate. This could be used for the counter circuit.
Hmmm...my car is with my friend this weekend...I will check it out the second I can. I left the casing for the steering column open for easy access
 

Les Jones

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Hi AK,
My understanding is the kimbear wants to use a +12 volts signal to trigger the unit. That is my interpretation of his statement "12v dc is available at the turn signal switch, which is simply a on/off/on arrangement with the center position as off. Using steering diodes, I can combine the 2 into 1 =12vdc signal when either one is activated." in post #1o I understand this to be a solid 12 V (I.E not pulsed.) Also I think you must have been half asleep when you drew the schematic in post #19 Your negative OR gate output from the blinker inputs is connected directly to ground. I think your circuit will pulse the bleeper and LED on at about 0.05 Hz (Once every 20 seconds) Also a 1% tolerance resistor for R1 seems pointless when C1 will probably have a tolerance of +50% -20%
kimbear can you conform if my understanding of the signal inputs is correct ?

Les.
 
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