On 7/31/2022 9:10 PM, jlarkin@highlandsniptechnology.com wrote:> On Sun, 31 Jul 2022 19:54:46 -0500, amdx <amdx@knology.net> wrote: > >> On 7/31/2022 2:58 PM, jlarkin@highlandsniptechnology.com wrote: >>> On Sun, 31 Jul 2022 10:56:27 -0500, amdx <amdx@knology.net> wrote: >>> >>>> I'd like to setup a high Q LC to receive a local Radio station probably >>>> charging a cap, when the charge is high enough flash an LED. >>>> Maybe set the trigger point of an SCR, or could just a zener do it. I >>>> don't have LT spice, so please don't post and answer with that. >>>> >>>> Thanks, Mikek >>> I expect that a strong radio station could light an LED visibly >>> continuously, given a good well-matched antenna. Or charge a cap and >>> use a discharge circuit to get bright blinks. >>> >>> Here's my high-voltage low current blinker: >>> >>> https://www.dropbox.com/sh/yaqbi52vbpo6uyc/AABPAczwj1zv26-fwI4LvJyha?dl=0 >>> >>> But LT Spice is free, easy to learn, and a wonderful tool for stuff >>> like this. >>> >> I was hoping to do it with just a coil and cap. I have some 6" coils with >> Q over 1000. Very high impedance a resonance, so might need a lower >> impedance pickup coil. >> Their Litz wire, so I don't want to tap them. > You might consider a tuned loop antenna. > > What frequency stations do you have nearby?I have a strong local on 1290, which is right about the Q peak of my 6" coils. I do have a 2 ft, loop antenna that will rotate and do azimuth tilt. I can put a portable radio in the middle of that and it makes big signal difference. I can also get 870 WWL in New Orleans on a portable :-) From Panama City Fl. Mikek -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus
Simple circuit to flash an LED from RF
Started by ●July 31, 2022
Reply by ●August 1, 20222022-08-01
Reply by ●August 1, 20222022-08-01
On Sun, 31 Jul 2022 20:04:53 -0700 (PDT), whit3rd <whit3rd@gmail.com> wrote:>On Sunday, July 31, 2022 at 6:12:02 PM UTC-7, amdx wrote: >> On 7/31/2022 7:35 PM, boB wrote: >> > On Mon, 01 Aug 2022 03:13:19 +0300, Klaus Kragelund >> > <klau...@hotmail.com> wrote: > >> >> Tuned LC with diode to big low leakage cap >> >> >> >> Then a BJT multivibrator, can operate in nA >> >> Assign very low duty cycle for LED > > >> > Yes, I was thinking an L-C circuit to boost the voltage at least. > >That's important because the 'diode' isn't usually as sensitive as a crystal set >(which has terrible breakdown, but good low-bias energy efficiency) >Antennae have impedance, is matters what kind of antenna you connect.A modern schottky diode is better than an old point-contact germanium. And an LED needs volts, so diode drop isn't a big deal.
Reply by ●August 1, 20222022-08-01
In article <tc788p$hbqe$1@dont-email.me>, amdx@knology.net says...> I'd like to setup a high Q LC to receive a local Radio station probably > >> charging a cap, when the charge is high enough flash an LED. > >> Maybe set the trigger point of an SCR, or could just a zener do it. I > >> don't have LT spice, so please don't post and answer with that. > >> > >> ������������������������������� Thanks, Mikek > >How far away from the station and whas there frequency and power ?
Reply by ●August 2, 20222022-08-02
On 01/08/2022 01:13, Klaus Kragelund wrote:> 31.07.22 22:58, jlarkin@highlandsniptechnology.com wrote: >> On Sun, 31 Jul 2022 10:56:27 -0500, amdx <amdx@knology.net> wrote: >> >>> I'd like to setup a high Q LC to receive a local Radio station >>> probably charging a cap, when the charge is high enough flash an LED. >>> Maybe set the trigger point of an SCR, or could just a zener do it. I >>> don't have LT spice, so please don't post and answer with that. >>> >>> ������������������������������� Thanks, Mikek >> >> I expect that a strong radio station could light an LED visibly >> continuously, given a good well-matched antenna. Or charge a cap and >> use a discharge circuit to get bright blinks.>> Here's my high-voltage low current blinker: >> >> https://www.dropbox.com/sh/yaqbi52vbpo6uyc/AABPAczwj1zv26-fwI4LvJyha?dl=0 >> >> But LT Spice is free, easy to learn, and a wonderful tool for stuff >> like this. >> > > Tuned LC with diode to big low leakage cap > > Then a BJT multivibrator, can operate in nA > Assign very low duty cycle for LEDI vaguely recall an ancient bipolar transistor low leakage thyristor functional equivalent that could be used to flash an LED brightly but very slowly depending on charging of a low leakage reservoir capacitor. It snapped into conduction when the voltage reached about 4v. It was briefly in vogue for flashing them in the early red LED era just prior to UJTs becoming common and cheap. -- Regards, Martin Brown
Reply by ●August 2, 20222022-08-02
On Sunday, July 31, 2022 at 8:54:55 PM UTC-4, amdx wrote:> On 7/31/2022 2:58 PM, jla...@highlandsniptechnology.com wrote: > > On Sun, 31 Jul 2022 10:56:27 -0500, amdx <am...@knology.net> wrote: > > > >> I'd like to setup a high Q LC to receive a local Radio station probably > >> charging a cap, when the charge is high enough flash an LED. > >> Maybe set the trigger point of an SCR, or could just a zener do it. I > >> don't have LT spice, so please don't post and answer with that. > >> > >> Thanks, Mikek > > I expect that a strong radio station could light an LED visibly > > continuously, given a good well-matched antenna. Or charge a cap and > > use a discharge circuit to get bright blinks. > > > > Here's my high-voltage low current blinker: > > > > https://www.dropbox.com/sh/yaqbi52vbpo6uyc/AABPAczwj1zv26-fwI4LvJyha?dl=0 > > > > But LT Spice is free, easy to learn, and a wonderful tool for stuff > > like this. > > > I was hoping to do it with just a coil and cap. I have some 6" coils with > Q over 1000. Very high impedance a resonance, so might need a lower > impedance pickup coil. > Their Litz wire, so I don't want to tap them.A high-Q circuit is going to be useless in this application, because you need to draw power which will spoil the Q of any high-Q circuit. The only use of a high-Q circuit would be for tuning, but with the power you are drawing off, it won't be high-Q anymore, just a tuned circuit. -- Rick C. - Get 1,000 miles of free Supercharging - Tesla referral code - https://ts.la/richard11209
Reply by ●August 2, 20222022-08-02
On Sunday, July 31, 2022 at 9:12:02 PM UTC-4, amdx wrote:> On 7/31/2022 7:35 PM, boB wrote: > > On Mon, 01 Aug 2022 03:13:19 +0300, Klaus Kragelund > > <klau...@hotmail.com> wrote: > > > >> 31.07.22 22:58, jla...@highlandsniptechnology.com wrote: > >>> On Sun, 31 Jul 2022 10:56:27 -0500, amdx <am...@knology.net> wrote: > >>> > >>>> I'd like to setup a high Q LC to receive a local Radio station probably > >>>> charging a cap, when the charge is high enough flash an LED. > >>>> Maybe set the trigger point of an SCR, or could just a zener do it. I > >>>> don't have LT spice, so please don't post and answer with that. > >>>> > >>>> Thanks, Mikek > >>> I expect that a strong radio station could light an LED visibly > >>> continuously, given a good well-matched antenna. Or charge a cap and > >>> use a discharge circuit to get bright blinks. > >>> > >>> Here's my high-voltage low current blinker: > >>> > >>> https://www.dropbox.com/sh/yaqbi52vbpo6uyc/AABPAczwj1zv26-fwI4LvJyha?dl=0 > >>> > >>> But LT Spice is free, easy to learn, and a wonderful tool for stuff > >>> like this. > >>> > >> Tuned LC with diode to big low leakage cap > >> > >> Then a BJT multivibrator, can operate in nA > >> Assign very low duty cycle for LED > > > > Yes, I was thinking an L-C circuit to boost the voltage at least. > > > > LTspice can be downloaded for free from www.analog.com > > > > I suggest you get it. > > > > boB > > > Ya, I had it for a while played with it had fun with it, I did some > circuits, went out and got subcircuits, all was cool and as I recall I was > trying to show how match was important to power transfer nothing major > just maximum power transfer, I posted it here > got a shit load of flack, was told I need to learn electronics before I > try LT spice. I just said Fuck it. Haven't touched it since.LTspice is a PITA. Some of your circuits will likely need custom modules. The documentation for these things is byzantine. You will need to use the LTspice groups for help and you will get multiple, conflicting advice. LTspice is not for the faint of heart. Also, you do need to understand electronics theory enough to know when your circuit is mucked up and lying to you. -- Rick C. + Get 1,000 miles of free Supercharging + Tesla referral code - https://ts.la/richard11209
Reply by ●August 2, 20222022-08-02
On Sun, 31 Jul 2022 10:56:27 -0500, amdx <amdx@knology.net> wrote:>I'd like to setup a high Q LC to receive a local Radio station probably >charging a cap, when the charge is high enough flash an LED. >Maybe set the trigger point of an SCR, or could just a zener do it. I >don't have LT spice, so please don't post and answer with that. > > ������������������������������� Thanks, MikekSo try charging a cap first. RL
Reply by ●August 2, 20222022-08-02
On a sunny day (Tue, 2 Aug 2022 05:36:37 -0700 (PDT)) it happened Ricky <gnuarm.deletethisbit@gmail.com> wrote in <e2885266-349e-4dfa-b728-6c4279190f09n@googlegroups.com>:>A high-Q circuit is going to be useless in this application, because you need >to draw power which will spoil the Q of any high-Q circuit. The only use >of a high-Q circuit would be for tuning, but with the power you are drawing >off, it won't be high-Q anymore, just a tuned circuit.You could use the high Q and a diode to slowly charge a capacitor. But need more info, field strength, frequency etc. For 10$ you can get a good RF detector on ebay, I have one. You could use a mechanical mirco-amp meter and have the hand touch an electrode. In my case I needed nothing, just a LED connected to my 27 MHz GPA antenna would flash any time the across the road neighbor turned on his transmitter, I asked him what power he was using (4 W was legal limit for CB here back then) but no answer to that question, some used more like 400 W (Italians I have heard).
Reply by ●August 2, 20222022-08-02
> On Sunday, July 31, 2022 at 9:12:02 PM UTC-4, amdx wrote: >> On 7/31/2022 7:35 PM, boB wrote: >>> On Mon, 01 Aug 2022 03:13:19 +0300, Klaus Kragelund >>> <klau...@hotmail.com> wrote: >>> >>>> 31.07.22 22:58, jla...@highlandsniptechnology.com wrote: >>>>> On Sun, 31 Jul 2022 10:56:27 -0500, amdx <am...@knology.net> wrote: >>>>> >>>>>> I'd like to setup a high Q LC to receive a local Radio station probably >>>>>> charging a cap, when the charge is high enough flash an LED. >>>>>> Maybe set the trigger point of an SCR, or could just a zener do it. I >>>>>> don't have LT spice, so please don't post and answer with that. >>>>>> >>>>>> Thanks, Mikek >>>>> I expect that a strong radio station could light an LED visibly >>>>> continuously, given a good well-matched antenna. Or charge a cap and >>>>> use a discharge circuit to get bright blinks. >>>>> >>>>> Here's my high-voltage low current blinker: >>>>> >>>>> https://www.dropbox.com/sh/yaqbi52vbpo6uyc/AABPAczwj1zv26-fwI4LvJyha?dl=0 >>>>> >>>>> But LT Spice is free, easy to learn, and a wonderful tool for stuff >>>>> like this. >>>>> >>>> Tuned LC with diode to big low leakage cap >>>> >>>> Then a BJT multivibrator, can operate in nA >>>> Assign very low duty cycle for LED >>> >>> Yes, I was thinking an L-C circuit to boost the voltage at least. >>> >>> LTspice can be downloaded for free from www.analog.com >>> >>> I suggest you get it. >>> >>> boB >>> >> Ya, I had it for a while played with it had fun with it, I did some >> circuits, went out and got subcircuits, all was cool and as I recall I was >> trying to show how match was important to power transfer nothing major >> just maximum power transfer, I posted it here >> got a shit load of flack, was told I need to learn electronics before I >> try LT spice. I just said Fuck it. Haven't touched it since.It's a bit of a pity that you let the opinions of others deprive you of a useful tool. Spice has its quirks, but it can help a lot, once you get the hang of it. Don't try to use it to simulate complete complex circuits. Jeroen Belleman
Reply by ●August 2, 20222022-08-02
On Tue, 02 Aug 2022 15:11:10 +0200, Jeroen Belleman <jeroen@nospam.please> wrote:>> On Sunday, July 31, 2022 at 9:12:02 PM UTC-4, amdx wrote: >>> On 7/31/2022 7:35 PM, boB wrote: >>>> On Mon, 01 Aug 2022 03:13:19 +0300, Klaus Kragelund >>>> <klau...@hotmail.com> wrote: >>>> >>>>> 31.07.22 22:58, jla...@highlandsniptechnology.com wrote: >>>>>> On Sun, 31 Jul 2022 10:56:27 -0500, amdx <am...@knology.net> wrote: >>>>>> >>>>>>> I'd like to setup a high Q LC to receive a local Radio station probably >>>>>>> charging a cap, when the charge is high enough flash an LED. >>>>>>> Maybe set the trigger point of an SCR, or could just a zener do it. I >>>>>>> don't have LT spice, so please don't post and answer with that. >>>>>>> >>>>>>> Thanks, Mikek >>>>>> I expect that a strong radio station could light an LED visibly >>>>>> continuously, given a good well-matched antenna. Or charge a cap and >>>>>> use a discharge circuit to get bright blinks. >>>>>> >>>>>> Here's my high-voltage low current blinker: >>>>>> >>>>>> https://www.dropbox.com/sh/yaqbi52vbpo6uyc/AABPAczwj1zv26-fwI4LvJyha?dl=0 >>>>>> >>>>>> But LT Spice is free, easy to learn, and a wonderful tool for stuff >>>>>> like this. >>>>>> >>>>> Tuned LC with diode to big low leakage cap >>>>> >>>>> Then a BJT multivibrator, can operate in nA >>>>> Assign very low duty cycle for LED >>>> >>>> Yes, I was thinking an L-C circuit to boost the voltage at least. >>>> >>>> LTspice can be downloaded for free from www.analog.com >>>> >>>> I suggest you get it. >>>> >>>> boB >>>> >>> Ya, I had it for a while played with it had fun with it, I did some >>> circuits, went out and got subcircuits, all was cool and as I recall I was >>> trying to show how match was important to power transfer nothing major >>> just maximum power transfer, I posted it here >>> got a shit load of flack, was told I need to learn electronics before I >>> try LT spice. I just said Fuck it. Haven't touched it since. > >It's a bit of a pity that you let the opinions of others deprive you >of a useful tool. Spice has its quirks, but it can help a lot, once >you get the hang of it.I have got people started on LT Spice, entering and running a basic circuit, in 5 minutes. I often use it instead of a calculator, for simple stuff like voltage dividers and rc circuits. Unlike a calculator, it leaves a record.> >Don't try to use it to simulate complete complex circuits.Not entire products, but pretty hairy subsystems. https://www.dropbox.com/s/dv9qiy2z3x2bxhk/P942_18.jpg?raw=1 As Mike said, the main function of Spice is to train your instincts.
