Simple transistorised 6V flasher for indicators

Hi, so I eventually got a layout & schematic for the CDI up on the "High Performance Tips" section. I have noticed that some people seem to like the idea of indicator's for their bikes & that a simple, roll ur own system hasnt been posted. Sooo, I have put together a prototype built around 2 common & cheap transistors, a PN100 & a PN200, using 5 resistors (1/2 watt), a minature trim pot (to control flash rate) & a 100uf/16V electrolytic capacitor. The whole thing, constructed on vero board is about the size of a small postage stamp, or 3/4" x 3/4", & about 1/4" thick. Running on 6V, it is designed to flash a #47 type 6V bulb, which is the type used in old pinball machines so should be bright enough. 2 units would be needed to have front & rear indicators using these bulbs, or just 1 unit if u used 0.4watt 6V bulbs. All up the prototype cost $2 to construct. I have just tested for 5 minutes to make sure it works, so now I'll run it for a few days then post the schematic.
I chose 6V to power so that a rechargeable battery can be used & charged off the white wire. Cheers

Ok, so I ran the flasher for a couple of hours with no problem. Using a 6 Volt #47 type bulb (bayonet style fitting) with an amber colored bezel gave good brightness. The #47 bulb is a 6.3V, 0.945W, or 0.15A bulb so 2 of these flasher's will be needed for front & rear indicators. As I said b4, the cost of 1 flasher is like, 2 bucks so thia shouldnt be a problem & being 3/4" x 3/4" x 1/4", a flasher is small enough to simply be enclosed in a piece of large diameter heatshrink with the ends siliconed up.
The flasher is wired as follows. The negative from the 6V battery goes to the flasher. The positive from the battery goes to the center terminal of the indicator switch. From there it goes to either left or right side indicator bulb, thru the bulb & back to the circuit board. Obviously both left & right side bulb go to a common point on the circuit board. The positive from the switch would go to both front & rear bulbs, just the front indicators would return to the flasher for the front indicators & the rear to the rear flasher. So,,, now I'll draw up a schematic & get my friend to post it as I did with the CDI layout & schematic.
For now, the parts list for one flasher is
Transistors, one of each,
PN100
PN200
Resistors, one of each,
220 ohm
1.5k
22k
33k
Minature trim pot
20k
Electrolytic capacitor
100uf/16V.
So,,, I'll get the schematic up.
While I think of it, the bayonet style #47 bulbs fit into those little insulated plastic sockets used for dash panel backlights in cars. They also have 2 leads, one fir each terminal connection on the bulb. Cheers

Hi KCVale, I know wot u mean. I've been using a small, 3 x AAA battery powered, 190 optic lumen LED flashlight with strobe feature clipped to the handle bars for this.
This flasher is designed to flash an incandescent, which would not have the same effect, tho I suppose it would still work using one of the hi efficiency LED's with a voltage dropping resistor wired in series with. I'll have to try it. Of course, the 2 transistors could be substituted with higher current types to allow much higher wattage bulbs to be used as well. The PN100 is an NPN type transistor & the PN200 is a PNP type. These transistors are good for up to 45V, so this flasher should work with 12V, tho u would maybe want to use a 25V/100uf electrolytic rather than a 16V. So I'll get the schematic up. Cheers

Ok, I will really try & get the schematic up tomorrow afternoon as I'm only working 1/2 a day. I do have some good news tho, I built another flasher tonight using the exact same circuit but substituted two much more powerful transistors, with equal success as before.
The PN100 (NPN type) & the PN200 (PNP type) are both 500mA devices.
The flasher I just built tonight uses a TIP31 (NPN type) & a TIP32 (PNP type) transistors. These devices are both 3A devices, or are rated for 6 times the current handling capability than the other types.
The only difference is the 2 types have a different pin out to each other.
The PN100 & PN200, if held with the flat face with writting on facing u & the pins at the bottom are from left to right;
Emitter, Base, Collector.
The TIP31 & TIP32, if held with the plastic face with writting on facing u & pins at the bottom are, from left to right;
Base, Collector, Emitter.
When I post the schematic I will include a diagram showing the denotation for Base, Emitter & Collector for both NPN & PNP types. I wont include a layout but with so few components u could breadboard them using wire links quite easily.
The TIP31 & TIP32 are just as commonly available as the other types. They are good for 40 Volts & the 3A rating is for continuous use so they will support much higher wattage bulbs than the other types, which were good for use with the #47 type bulb which is 6.3V/0.94W.
Use with 12 volt will be fine. I used a 100uf/25V electrolytic in this one.
I would really suggest using the TIP31 & TIP32 transistors. If u used a small heatsink on each one u could probably use normal auto indicatot bulbs, or bulbs of that type wattage. U will also only need to build one flasher as u could put 2 bulbs in parallel between the indicator switch & circuit on both sides, 1 front & 1 rear, as these are 3A continuous rated transistor's. As they are fladhing, & with heatsinks, u can exceed this by a bit. One thing, u must use 2 seperate heatsinks & they must be isolated from one another. One flasher, using heatsinks, could be built to fit in a 1" square cube. Cheers

Ok, so I bluetoothed 3 pics to my friend's phone & she's on her way home & will get them up here shortly.
One is a pic of the hand drawn schematic.
The second is a hand drawn pic of both device types showing the pin out connections for each type.
The third is a pic of the two prototypes showinf how physically small they are.
One thing I forgot was to mark the device's (transistor's) on the schematic to show the Emitter, Base & Collector for those who arent familliar with the schematic representation of these, so I'll quickly give u the lowdown here.
Ok, both devices, labelled PN100 & PN200 on the schematic will have a short vertical line on the left hand side which is the Base. Off to the right of this vertical line are two angled lines, one angled up, the other angled down. Notice that one of these has an arrow head at the end of it (right hand side). The one with the arrow head is the Emitter & the one without is the collector. Cheers

Ok, hopefully this will mean the schematic & pic showing transistor pin outs are up. Thank you very much to both KCVale & Scott D Lang in assisting me. Appologise but I really am dumb as dog sh*t when it comes to computers. Well, actually I only have a phone but I cant really use it very well either. Cheers

Well,,, not quite,, but if u click on the schematic with Ivans pics written under & then Scott D Lang under that in the link, u'll get the 2 pix we need. Maybe someone can get them up here properly because I cant. Cheerz

KCVale to the rescue again. Thanks heaps for that KCV. I only have an el cheapo nokia phone, tho I'm sure its capable of a lot more than wot I am of getting it to actually do it.
I dont know if people are interested in a flasher or not, but using the larger transistor's, the flasher will operate on anything from 6V to 24V & will flash both front & rear indicators simultaneously if the bulbs are wired in parallel pairs between the indicator switch & circuit board. It will also allow the use of much higher wattage bulbs, like the BA15d types which are an approved park or side/indicator bulb for cars, motorcycles & mopeds & available in 6V, 12V & 24V variants. The BA15d is a bayonet style bulb but both connectors are at the bottom & isolated from the metal base, so are idealy suited to this application. The fittings are used as the park/emergency flashing lights on cars so 4 of could easily scrounged.
One thing, the schematic shows the smaller transistors & I forgot to mark the transistor pin connections on it, tho the text gives instructions on.
So,,,, if anyone would like a schematic drawn up around the bigger & much more powerful transistors (& showing transistor connections) up here, & has the ability to post it here, PM me ur email address & I'll draw it up & email u a pic,,, maybe a layout as well. Cheers

KCVale to the rescue again. Thanks heaps for that KCV. I only have an el cheapo nokia phone, tho I'm sure its capable of a lot more than wot I am of getting it to actually do it.
I dont know if people are interested in a flasher or not, but using the larger transistor's, the flasher will operate on anything from 6V to 24V & will flash both front & rear indicators simultaneously if the bulbs are wired in parallel pairs between the indicator switch & circuit board. It will also allow the use of much higher wattage bulbs, like the BA15d types which are an approved park or side/indicator bulb for cars, motorcycles & mopeds & available in 6V, 12V & 24V variants. The BA15d is a bayonet style bulb but both connectors are at the bottom & isolated from the metal base, so are idealy suited to this application. The fittings are used as the park/emergency flashing lights on cars so 4 of could easily scrounged.
One thing, the schematic shows the smaller transistors & I forgot to mark the transistor pin connections on it, tho the text gives instructions on.
So,,,, if anyone would like a schematic drawn up around the bigger & much more powerful transistors (& showing transistor connections) up here, & has the ability to post it here, PM me ur email address & I'll draw it up & email u a pic,,, maybe a layout as well. Cheers