pieterw0

Hi MP Thanks for the advise I got it working in a way. Pieter

Thanks! ;D

Thanks for the feedback tnk2k and Ante I will scratch around a bit and see what I can come up with. Pieter

Audioguru I am still on the old circuit. (Original) Pieter

Ante You got me very interested in your suggestion. The small piece of metal, is this attached to the shaft with the inductor a few inches away? Could you give more info as far as the specs of the inductive sensor. Perhaps if you have something on this type of configuration I would be happy to try it. Thanks Pieter

Hi Ante I was actualy playing around with audioguru and the 5th wheel. As you might have noticed from his posting that in my opinion I think he was sarcastic. So I humored him. Anyway I was looking at magnetic sensors as well as reflective laser pick up's that works on a shaft. (Prop shaft or drive shafts).There is a variety of sensors (pick-up's) available. If one would go for the magnetic version then you would need something like a belt with magnets evenly spaced to go around the shaft. With the laser, you would need a piece of tape with black markings evenly spaced around the shaft. http://www.shumatech.com/dro-350/add-ons.htm http://www.jeffree.co.uk/Pages/speedmeasurement.html I still think it is posible to change a component value to slow the response time in the original circuit to avoid the anoying beeps. . . . . . . . . . ;D I would welcome any suggestions. Pieter

Audioguru It is a speed alert. you called it a long distence speed alert. ;D I think I will settle for the 5th wheel. ??? ;D 8) Any ideas what size? Pieter

Audioguru I meant to ask you. I have the project working in a way. With this unit working on rpm it should warn on what ever revs are set. In my car the unit is set for 2000rpm which represents approximately 60 kph. When you pull away from stand still in first gear the revs reaches 2000rpm. Switching to second gear, before changing to third gear it reaches 2000 rpm. So whilst changing gears the alarm sounds every time the revs reaches 2000rpm. My question!!!!!!!!!!!!!!! Is there a way that one can delay the alarm if the revs changes irregularly? Or is there a way to make the unit respond ONLY when the revs has stabilized? Any ideas to take the annoying beeps away whilst changing gears would be appreciated. Thanks Pieter

Hi Audioguru Sorted it out THANKS! Who made electronics so complicated anyway? ;D Pieter

Hi Audioguru The black lines does represents the connections as you sugest. The switch also selects each pot individually. What happens is that instead of each (SELECTED) pot adjusting between 0 and 100K, each selected pot adjust only between 55K and 85K. It doesn't go to zero and it doesn't go to near 100K. How ever, If I only use ONE pot the adjustment goes between 0 and 100K This is what I mean that it means (averages) the values Pieter

Hi Audioguru What is wrong with this picture. This is a Make before break single pin select switch. This configuration means the values of the 4 pots. Is there a different way of doing it or should I rather get a switch that select 2 pins simultaneously so that each pot could be selected individually? Thanks Pieter

Hi Audioguru In the right up the author sugested the following. Depending on the engine's cylinders number, R11 can be unable to set the device properly. In some cases you must use R11=200K and R12=100K or less. I did follow his advice but with with little change. So I thought I could make changes somewhere else. With your advice I have more room for improvement. The thing is that I don't want to tamper with components that might afect others. Thus causing more harm than good. I will try your advise and let you know Thanks Pieter

Hi Audioguru A small problem. I need to change some resistor values in the warning part of the circuit.(Old circuit) When I set R11 to 47K it moans on 1000 rpm. When I adjust R11 to 0 the highest revs I get is 1500 rpm. I need to gain at least another 2000 rpm. Because I cant go further than zero I assume that lowering some resistor values, would do the trick. So I’m not sure which ones. Any suggestions as to what resistors I could change. Thanks Pieter

Hi Audioguru and guys. My humblest apologies to every one on the forum !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I found out by accident that with pin 4 on IC1 connected works. The fact of the matter is that my computer is on the work bench. Having said this the magnetic pulses generated by the computer screen caused D1 to light. No matter in whatever position you turn R8 the led stayed lit. This was also the reason that the buzzer went beep on a per second basis. My computer hanged and I had to switch it off. Only when I did this I noticed that the led had gone dead. After restarting I moved away from the computer. The further away I moved the dimmer it got. So for about 2m + D1 goes out completely. To give you an indication how strong the pulses is, it as if the LED gets full voltage. The brightest a LED can go. I never realized that this was a factor. I am trying to kick myself in the butt but I can’t reach. Sorry guys. I am reconstructing the unit off all the damage I did to the tracks now so will let you know what happens. I will also try the new design. Who knows. Maybe both could be posted with pc boards on the web site. Pieter

Hi Audioguru and guys. Could you go back a few posts please! There is a few questions that I would like for you to answer, if it is not to much trouble. To answer Dazza’s question. I have a mechanical speedometer. This brings about a different topic. The application I want is a unit that if I preset it to 60mph then it must switch the buzzer and LED on at that point. So in other words all above 60mph this unit must moan until I reduce speed below 60mph. Once below 60mph the warnings must stop. This is actually all I need. The Speed limit alert circuit on the website doesn’t work so I’m looking at alternatives. BUT As far as I know the tachometer is the only way to go as far as wireless is concerned. Once you go the speedometer way you need a fixture like a shaft that you can count the number of revolutions per minute. This will be to expensive. I would rather settle for a small inexpensive way to warn me of over speeding. (Something I am guilty of many times) Audioguru You spoke about the 4 cascaded inverters. IC1 and IC2 is not that hot. Not to forget. IC3a also has some amplification. You must move the unit back and forth and sideways in the cabin to get a proper signal. The signal I found was basically next to the wind screen. (Not a good position) The LM2917 also has some amplification in the first of it’s three parts. If you think that the 4 cascaded inverters discussed with Alum, will work better I would rather go for that. Give me the schematic for a decent Speed alert with a buzzer and LED warning and I will build it. Just for interest sake: I have rebuilt the L1, IC1 and IC2 section again. If pin 4 of IC1 is connected D1 stays lit and doesn’t pick up a signal. Once disconnected D1 goes out. It starts flashing when a signal is detected. Pieter

Hi Audioguru Yes it’s excellent. This is what I had in mind. Just a few questions. 1) The old IC1 and IC2 will amplify the signal to keep it long range. R8, D1 will still indicate the best sensing position of the unit. Is this correct? 2) Pin 3 of IC LM2917 with the trimmer will select the different cylinders. 4, 6 and 8. Is this correct? Or do I use the trimmer on pin 3 to set the required speed? The load is the warning part. Is this correct? Thanks Pieter

Hi Audioguru I want to try a new concept. In fact, the one you suggested. This is the latest as you said. This IC converts frequency to volts. All in one. Hope I’m right! So if you don’t mind lets start with the pick up and amp for now. I would like to keep it wireless. I have come to a point where the range on the old one was OK. I now need to incorporate L1 and IC 1 into this diagram. If I am correct. IC1 amplifies the signal. IC2A further amplifies the pulses and IC2B to IC2F inverters provide clean pulse squaring but, Do I need IC 2? As I see it LM2917 already gives out a clean voltage. I am not a designer so I really need some expert advice and guidance. If possible could you draw me a schematic of how one would do this with the necessary resistors and caps. I would really appreciate your input Thanks Pieter

Hi Audioguru Let's start from the beginning if you don't mind. One must accept that there is an inballance in the curcuit as it is. If you look at the schematic. From L1 right through to IC 4098 and D1 and R9. This section picks up the signal to about 1.5 m. Why does the second part not corespond with part 1. Surely the second part must warn from where ever the first part picks up the signal. At the moment it is as if the second part is working on it's own. I have to move the unit closer to about 30cm from the spark plugs before it warns. I am thinking logical here now. It seems as if the second part is ignoring the fist parts signal. As I said. the second part must warn from where ever the first part picks up the signal. IC3A is used as a frequency discriminator, its pin 6 going firmly high when speed limit (settled by R11) is reached. IC3B, the transistors and associate components provide timings for the signaling part, formed by LED D5 and piezo sounder BZ1. D3 introduces a small amount of hysteresis. Any Ideas. Could one of the caps maybe be the cause of this? I don't know. Just asking. Pieter Ok this problem is also sorted out now. I have disconnected R10. The unit sounds from the same distance as what D1 picks up the signal. One final question!!!!!!!!!!!!!!!!!!! How could i possibly increase the range of the pick up. What determine the range. Is it the size of L1 or is it also certain values of the resistors in conjunction with L1? Thanks

Hi Audioguru It is fact. I agree with you. It is shown as hidden power pins, but what I did was to start cutting tracks. Remember I said that D1 and D5 with it's buzzer would sound from beginning to end non stop. I have even moved the unit next to the spark plugs and wires and wouldn't change. I then disconnected pin 7 & and 4. The unit was then dead. I connected pin 4 again and there was nothing. Then I disconnected pin 4 again and connected pin 7 and all of a suden I got a reaction. The reaction was that D1 responded to about 1.5 meter from the spark plugs. If I turn around away from the engine D1 does not light. When I turn back towards the running engine D1 starts to flash again. D5 and buzzer on the other hand only responds about 30cm from the spark plugs. When I move the unit further than that 30cm it stops to sound. With this in mind. R11 was set to about 1/4 of it's adjusting ability. With the unit about 30cm away from the spark plugs nothing sounds. When I ref the engine to a certain RPM D5 and buzzer starts to sound. When I release the throttle on the carburetor D5 and buzzer stops to sound. This tells me that the unit is now working, but not as it should. If D1 picks up a frequency to about 1.5 meter then why does D5 and buzzer only works to about 30cm. This means that If I have to reconnect pin 4 to equalize D1 and D5, something else must be wrong. As I said. I know nothing about designing. I could build a curcuit. That is about it. It would be nice if someone in the forum could build the unit and see if it works. If it works good. If it doesn't then the guru's can at least find the problem and post a proper curcuit with pc board that works. This is a nice project and I would hate to see that the money spend on the parts was wasted. Thanks Again Pieter

Hi Audioguru Ok! I have some success. I had a look at the data sheets for IC1, IC2 and IC3. On the data sheet for IC 1, I noticed that pin 4 and 7 are not widely used in some of the app examples. I disconnected pin 4 and “Walla”. It works. The only drawback of this circuit is that it is effective at 30cm from a plug wire. Beyond this point it doesn’t work. I Have tried different coils with only little improvement. The conclusion I came to, if I want to keep it “WIRELESS” I would have to split the project into a transmitter and a receiver. The transmitter transmitting the pulse frequency and the receiver receiving the frequency and converting it to volts in order to be able to adjust the required setting. Now I had a look at the Gasoline Engine Tachometer IC LM2917 that you refered me to and thought it has much less parts. The problem with this is that the IC already converts the frequency to volts, so I can’t use that in the transmitter I am a hobbyist. I haven’t got a clue how to even begin to design an application. What I would like for you or any one in the forum to help me with is; Where do I start. 1) I need a configuration to pick up the pulses and transmit it to the receiver. 2) I need a configuration to receive the pulses. (This is the part where the frequency needs to be changed to volts (I THINK). Within this board I must have the ability to select a certain speed and an alarm to warn if the speed is exceeded. If I have it correct. You select a certain volt and if the voltage exceed the set voltage the alarm sounds and the led flashes. Thanks Pieter

Hi audioguru I havn't thought of trying the project in this state. I will try the way you sugested. I have gone to the RED FREE CURCUIT DESIGNS web page. At the bottom of the page there is buttons e-mail and questions. I have posted a few e-mails without any reply. If this is the e-mail you are talking about then I won't even bother. As I said he doesn't even reply to the e-mails you send. Is there perhaps any other Speed Alert curcuits available that you know of that works? If so, could you direct me there. Thanks again Pieter

Hi audioguru What happens is this. When I attach the power D1 lights up and stays on. D5 flashes and the buzzer sounds on a per second basis. This all happens until I disconnect the battery or when I switch the unit off. So if you recon that the Pc board is ok then that means that the circuit is wrong. I would really like to make this circuit work. Do you know of any one that has built this project with success. Or is it posible to get in touch with the author of this circuit. The other question is, Was this project ever built to prove that it works or was this just a theory design? Thanks Pieter

audioguru Just to confirm! The common or third legs of R8 and R11 is conected (Wiper function). R8 and R11 is both mounted on the project box for easy acsess. I have checked the Pcboard layout again. Pieter

Thanks for responding Yep this is the one. No I have not substituted any parts. For R9 I have used 470 ohm and R20 150 ohm. What does concern me is the IC4069 layout. I could be wrong there but i'm not sure. IC1 = TL061CN IC2 = CD4069UBE IC3 = CD4098BE Transistors = BC238B All the other parts are standard. I still have a gut feeling that the pc board layout could have a flaw but I can't see it. Thanks Pieter (The two holes above R16 is for a bridge)

Hi guys I am new to this forum and hope I can get some assistance. I recently discovered the Electronics lab web site and decided to build the Speed Alert. The project is finish but has a problem. Still on the work bench, when I attach the battery the beeper and the LED working together lights and sounds on a per second bases. (As it should when it detects the set speed) I have double checked my pc board, components, tracks and all. I can’t find the problem. It is possible that I could have made an unknown error with the layout of the board. Is there someone that could assist me in this regard. Or perhaps offer an existing pc board layout that is working. Alternatively I will post the layout I have made, if it will help. Thanks in advance Pieter