I built an alarm circuit from a book I bought called Make Electronics by Charles Platt. https://drive.google.com/file/d/1NxvKdZCqykuSjBvPVoWz_MEMhKYMMz9E/view?usp=sharing The said circuit produces a siren type sound on a buzzer so I added an led through a resistor, a 10k pot and a LDR. I then connected the centre pin of the 10k pot to pin 2 on the top IC555 shown on the schematic Working version of the circuit https://drive.google.com/file/d/1NwYnNkljKLd7ORmZ16VYrtb7ZwCsvAn_/view?usp=sharing As the said circuit was working as I wanted with the ldr and buzzer, I built another of the same circuit. On this 2nd circuit, the led goes off when I adjust the 10k pot, but the sound does not. It does on the first circuit I built. Thanks
Amateur alarm circuit problem
Started by ●November 22, 2020
Reply by ●November 23, 20202020-11-23
On 22/11/2020 13:05, RobH wrote:> I built an alarm circuit from a book I bought called Make Electronics by > Charles Platt. > > https://drive.google.com/file/d/1NxvKdZCqykuSjBvPVoWz_MEMhKYMMz9E/view?usp=sharing > > > The said circuit produces a siren type sound on a buzzer so I added an > led through a resistor, a 10k pot and a LDR. I then connected the centre > pin of the 10k pot to pin 2 on the top IC555 shown on the schematic > > > Working version of the circuit > https://drive.google.com/file/d/1NwYnNkljKLd7ORmZ16VYrtb7ZwCsvAn_/view?usp=sharing > > > As the said circuit was working as I wanted with the ldr and buzzer, I > built another of the same circuit. > > On this 2nd circuit, the led goes off when I adjust the 10k pot, but the > sound does not. It does on the first circuit I built. > > ThanksIf anyone has replied to my post, I'm not seeing them.
Reply by ●November 24, 20202020-11-24
On 2020-11-22, RobH <rob@despammer.com> wrote:> I built an alarm circuit from a book I bought called Make Electronics by > Charles Platt. > > https://drive.google.com/file/d/1NxvKdZCqykuSjBvPVoWz_MEMhKYMMz9E/view?usp=sharing > > The said circuit produces a siren type sound on a buzzer so I added an > led through a resistor, a 10k pot and a LDR. I then connected the centre > pin of the 10k pot to pin 2 on the top IC555 shown on the schematic > > > Working version of the circuit > https://drive.google.com/file/d/1NwYnNkljKLd7ORmZ16VYrtb7ZwCsvAn_/view?usp=sharing > > As the said circuit was working as I wanted with the ldr and buzzer, I > built another of the same circuit. > > On this 2nd circuit, the led goes off when I adjust the 10k pot, but the > sound does not. It does on the first circuit I built. > > ThanksWith the 555 it's all about woltages, check that the voltages on the 555 inputs (pins 2,6,4, and 5) are what you expect them to be -- Jasen.
Reply by ●November 24, 20202020-11-24
On Mon, 23 Nov 2020 20:13:49 +0000, RobH <rob@despammer.com> wrote as underneath :>On 22/11/2020 13:05, RobH wrote: >> I built an alarm circuit from a book I bought called Make Electronics by >> Charles Platt. >> >> https://drive.google.com/file/d/1NxvKdZCqykuSjBvPVoWz_MEMhKYMMz9E/view?usp=sharing >> >> >> The said circuit produces a siren type sound on a buzzer� so I added an >> led through a resistor, a 10k pot and a LDR. I then connected the centre >> pin of the 10k pot to pin 2 on the top IC555 shown on the schematic >> >> >> Working� version of the circuit >> https://drive.google.com/file/d/1NwYnNkljKLd7ORmZ16VYrtb7ZwCsvAn_/view?usp=sharing >> >> >> As the said circuit was working as I wanted with the ldr and buzzer, I >> built another of the same circuit. >> >> On this 2nd circuit, the led goes off when I adjust the 10k pot, but the >> sound does not. It does on the first circuit I built. >> >> Thanks > >If anyone has replied to my post, I'm not seeing them.Not surprising - you have not made it easy to see exactly what you have done with the two circuits exactly as built side by side (not a breadboard picture). Why should anyone waste their time when you cannot be bothered yourself.
Reply by ●November 24, 20202020-11-24
On Sun, 22 Nov 2020 13:05:12 +0000, RobH <rob@despammer.com> wrote:>I built an alarm circuit from a book I bought called Make Electronics by >Charles Platt. >Maybe you want to draw your circuit into Micro-Cap http://www.spectrum-soft.com/index.shtm It's easy. The run the simulation. That's how the professionals do it. No soldering anymore. At least you should draw the circuit as you modified it. I am not sure to understand your description. w.>https://drive.google.com/file/d/1NxvKdZCqykuSjBvPVoWz_MEMhKYMMz9E/view?usp=sharing > >The said circuit produces a siren type sound on a buzzer so I added an >led through a resistor, a 10k pot and a LDR. I then connected the centre >pin of the 10k pot to pin 2 on the top IC555 shown on the schematic > > >Working version of the circuit >https://drive.google.com/file/d/1NwYnNkljKLd7ORmZ16VYrtb7ZwCsvAn_/view?usp=sharing > >As the said circuit was working as I wanted with the ldr and buzzer, I >built another of the same circuit. > >On this 2nd circuit, the led goes off when I adjust the 10k pot, but the >sound does not. It does on the first circuit I built. > >Thanks
Reply by ●November 24, 20202020-11-24
On 24/11/2020 07:02, Charlie+ wrote:> On Mon, 23 Nov 2020 20:13:49 +0000, RobH <rob@despammer.com> wrote as > underneath : > >> On 22/11/2020 13:05, RobH wrote: >>> I built an alarm circuit from a book I bought called Make Electronics by >>> Charles Platt. >>> >>> https://drive.google.com/file/d/1NxvKdZCqykuSjBvPVoWz_MEMhKYMMz9E/view?usp=sharing >>> >>> >>> The said circuit produces a siren type sound on a buzzer so I added an >>> led through a resistor, a 10k pot and a LDR. I then connected the centre >>> pin of the 10k pot to pin 2 on the top IC555 shown on the schematic >>> >>> >>> Working version of the circuit >>> https://drive.google.com/file/d/1NwYnNkljKLd7ORmZ16VYrtb7ZwCsvAn_/view?usp=sharing >>> >>> >>> As the said circuit was working as I wanted with the ldr and buzzer, I >>> built another of the same circuit. >>> >>> On this 2nd circuit, the led goes off when I adjust the 10k pot, but the >>> sound does not. It does on the first circuit I built. >>> >>> Thanks >> >> If anyone has replied to my post, I'm not seeing them. > > Not surprising - you have not made it easy to see exactly what you have > done with the two circuits exactly as built side by side (not a > breadboard picture). Why should anyone waste their time when you cannot > be bothered yourself. >This is why I hate asking questions here. No help, just castigated.
Reply by ●November 24, 20202020-11-24
On 24/11/2020 07:11, Helmut Wabnig wrote:> On Sun, 22 Nov 2020 13:05:12 +0000, RobH <rob@despammer.com> wrote: > >> I built an alarm circuit from a book I bought called Make Electronics by >> Charles Platt. >> > > > Maybe you want to draw your circuit into Micro-Cap > http://www.spectrum-soft.com/index.shtm > > It's easy. The run the simulation. > That's how the professionals do it. No soldering anymore. > > At least you should draw the circuit as you modified it. > I am not sure to understand your description. > w. > > >Thanks but there is nothing on that site for linux machines.
Reply by ●November 24, 20202020-11-24
RobH wrote:> This is why I hate asking questions here. No help, just castigated.You're asking people to compare a schematic circuit diagram to a breadboard built circuit, that's over the threshold most people are willing to get into. Why not provide a similar schematic showing your alterations?
Reply by ●November 24, 20202020-11-24
On 24/11/2020 08:41, Andy Burns wrote:> RobH wrote: > >> This is why I hate asking questions here. No help, just castigated. > > You're asking people to compare a schematic circuit diagram to a > breadboard built circuit, that's over the threshold most people are > willing to get into. > > Why not provide a similar schematic showing your alterations? > >Ok, I take your point. I have added the 10k pot, led and ldr onto the original schematic. It's the best I can do, I'm afraid, and hope it's clear enough. https://drive.google.com/file/d/1ObLBgJfce4fMPrvRTk5emIRcJzxhNWOt/view?usp=sharing
Reply by ●November 24, 20202020-11-24
On 24/11/2020 05:40, Jasen Betts wrote:> On 2020-11-22, RobH <rob@despammer.com> wrote: >> I built an alarm circuit from a book I bought called Make Electronics by >> Charles Platt. >> >> https://drive.google.com/file/d/1NxvKdZCqykuSjBvPVoWz_MEMhKYMMz9E/view?usp=sharing >> >> The said circuit produces a siren type sound on a buzzer so I added an >> led through a resistor, a 10k pot and a LDR. I then connected the centre >> pin of the 10k pot to pin 2 on the top IC555 shown on the schematic >> >> >> Working version of the circuit >> https://drive.google.com/file/d/1NwYnNkljKLd7ORmZ16VYrtb7ZwCsvAn_/view?usp=sharing >> >> As the said circuit was working as I wanted with the ldr and buzzer, I >> built another of the same circuit. >> >> On this 2nd circuit, the led goes off when I adjust the 10k pot, but the >> sound does not. It does on the first circuit I built. >> >> Thanks > > > With the 555 it's all about woltages, check that the voltages on the > 555 inputs (pins 2,6,4, and 5) are what you expect them to be > >I don't know what the voltages are supposed to be nor expected them to be, but here are my findings if they are any use; Pin 2 No Led nor pot 3v, with led on and pot connected , it fluctuates between 5v and 6.8v With the led turned off by the pot, 7v decreasing With the led on, turned on by the pot, between 5v and 6.8v Pin 4 No Led nor pot 9v, with led on and pot connected , 9v With the led turned off by the pot, 9v With the led on, turned on by the pot, 9v Pin 5 No Led nor pot, 5.9v with led on and pot connected , 5.9v With the led turned off by the pot, 5.9v With the led on, turned on by the pot, 5.9v Pin 6 No Led nor pot, 3v with led on and pot connected , between 5v and 6v With the led turned off by the pot, 5.5v With the led on, turned on by the pot, between 5.2v an 6.5v