Police flasher project?

[marvel6869]

In my cirucit, you will see I have a voltage divider on the base of each transistor to turn it off.
Without the voltage divider, the transistor will not turn off.
Is that enough proof?
Why don't you actually build the circuit and prove it will work, before putting it on the web?

do ya have a pcb layout for this flasher....

 

[Boncuk]

In my cirucit, you will see I have a voltage divider on the base of each transistor to turn it off.
Without the voltage divider, the transistor will not turn off.
Is that enough proof?
Why don't you actually build the circuit and prove it will work, before putting it on the web?

Nope! It's not more proof than mine, which you don't accept.

I normally simulate circuits or parts thereof using Proteus ISIS before designing the circuit board. The actually built circuits either proved the positive simulation results or the flaws (as already shown during simulation).

On the other hand it is a matter of politeness to prove a statement, and not force others to prove your statement was wrong.

Your statement clearly said: "That circuit won't work."

So it's your turn to prove your statement!

My proof is as follows:

counter output H, timer output H - UB=0.872017V,
counter output H, timer output L - UB=0.372356V, which turns the transistor off.

Refer to the voltage probes at the base resistor shown in the attached simulation screenshots.

Boncuk

 

[Boncuk]

i just want more simple circuit and also work as flasher.....

Hi,

here is a very simple circuit. Flashing rate is variable in a wide range.

Just flip S1 left and right at the desired flash rate.

 

[marvel6869]

hi,

here is a very simple circuit. Flashing rate is variable in a wide range.

Just flip s1 left and right at the desired flash rate. :d

hehehehe :d what i mean sir that the circuit would not be so complex to assemble :d

 

[colin55]

Yes, Boncuk, your circuit will work. Build 10,000 of them and I will buy them.

 

[Boncuk]

Yes, Boncuk, your circuit will work. Build 10,000 of them and I will buy them.

Don't you require a quote before "ordering"?

How much lead time do you want?

 

[Boncuk]

hehehehe :d what i mean sir that the circuit would not be so complex to assemble :d

If you wish I will provide a PCB layout design.

Before I do that I will build the circuit on a breadboard to recheck the simulation results.

Assembling is not complex. Even trained monkeys can do it.

Boncuk

 

[marvel6869]

If you wish I will provide a PCB layout design.

Before I do that I will build the circuit on a breadboard to recheck the simulation results.

Assembling is not complex. Even trained monkeys can do it.

Boncuk

please can you give mi a pcb lay out.. i really like it....

 

[colin55]

Assembling is not complex. Even trained monkeys can do it.

I thought that even a trained monkey could see the cirucit will not work.

 

[audioguru]

The circuit with the CD4017 doesn't flash the LED four times because its outputs Q0 to Q3 light the LED continuously then it turns off for two clock cycles before it is reset.

The diode connected to the base of the transistor won't turn it off but it might cause the LED to dim slightly. A Schottky diode might work if it is not too cold.

 

[colin55]

A trained monkey would use a Schottky diode. But, then again, he might say the voltage drops of the diode and the low from the 555 necessitates a voltage divider on the base of the buffer transistor. Trained monkeys are very smart, you know.
In the meantime I have put it on my website, under: Spot The Mistake, to help my readers design circuits that WORK.

 

[Boncuk]

A trained monkey would use a Schottky diode. But, then again, he might say the voltage drops of the diode and the low from the 555 necessitates a voltage divider on the base of the buffer transistor. Trained monkeys are very smart, you know.
In the meantime I have put it on my website, under: Spot The Mistake, to help my readers design circuits that WORK.

Whatever turns you on!

 

[Mr RB]

You guys are so funny. This thread reads like train wreck in slow motion.

 

[Boncuk]

You guys are so funny. This thread reads like train wreck in slow motion.

I'd tend to say it has turned in a kind of religious war.

 

[Boncuk]

The circuit with the CD4017 doesn't flash the LED four times because its outputs Q0 to Q3 light the LED continuously then it turns off for two clock cycles before it is reset.

Nobody asked for four flashes, just three. That's exactly what it does.

 

[Boncuk]

I thought that even a trained monkey could see the cirucit will not work.

Recall your yesterday's post:

Yes, Boncuk, your circuit will work. Build 10,000 of them and I will buy them.

Now, where is the truth?

 

[marvel6869]

Here is another one.

I doesn't strobe three times but alternates dual strobes with dual LEDs. (see attachment)

Speed is variable between 10 and 20Hz.

Boncuk

mr BOncuk you mean dual flash like twice on R & Twice on the L.

you mean this one from this video --->>>>Police Emergency Flasher - VidoEmo - Emotional Video Unity

 

[Boncuk]

Hi Marvel,

exactly that with the difference that my circuit uses two LEDs to flash alternating.

It's no problem to add more LEDs, but the design must be changed for higher current transistor drivers for the LEDs.

A 9V Alkali battery won't do the job for long. In the video 12 LEDs per channel are used. Blue LEDs normally have a forward voltage of 3.5V, which means 6 parallel strings of two series LEDs must be used. The current flow will be ~120mA at full power, depleting the battery quickly.

I can't build the three flasher circuit at this time since I don't have a 4017 on hand. Local shops do not provide CMOS ICs and I must travel to Bangkok to get some.

Boncuk

 

[colin55]

The man in the corner-store, in the electronics market, has FutureKit kits and one of the kits will have a 4017.

And there are lots of shops there that specialise in chips, chips, chips. just nearby.
Build it and you will see why it doesn't work.

 

[marvel6869]

Hi Marvel,

exactly that with the difference that my circuit uses two LEDs to flash alternating.

It's no problem to add more LEDs, but the design must be changed for higher current transistor drivers for the LEDs.

A 9V Alkali battery won't do the job for long. In the video 12 LEDs per channel are used. Blue LEDs normally have a forward voltage of 3.5V, which means 6 parallel strings of two series LEDs must be used. The current flow will be ~120mA at full power, depleting the battery quickly.

I can't build the three flasher circuit at this time since I don't have a 4017 on hand. Local shops do not provide CMOS ICs and I must travel to Bangkok to get some.

Boncuk

thank you alot. now the next challeng will be building a PCBLAYOUT