Driver to drive?

John Fields · Aug 15, 2013

On Tue, 13 Aug 2013 13:03:10 -0700 (PDT), "dcaster@krl.org"
<dcaster@krl.org> wrote:

On Tuesday, August 13, 2013 2:46:06 PM UTC-4, TTman wrote:
Any simple way to dump 500Watts fixed @100 volts ? Or is it easier to have

5 x 100R 100Watt resistors and a big heat sink ? test time would be

1minute...

Heathkit used to sell a load for use with transmitters. If I recall correctly it was about ten 2 watt resistors suspended in a gallon of oil.

Dan

---
http://www.orcadxcc.org/content/cantenna_va7jw.pdf

--
JF

John Fields · Aug 15, 2013

On Wed, 14 Aug 2013 13:53:33 -0700 (PDT), eric@bauld.com wrote:

There is no reset pin I am aware of, the SR Latch is constructed from two NOR gates on a quad input NOR gate IC.
If the latch was fully embedded into a IC instead of constructed from two NOR gates.. not sure I understand how the reset works in that case. Do you know of a chip that has that functionality? Just so I can see it and try to figure out how that relates to what was previously brought up.

-E

---
So far, no mention has been made as to how the latch's other input is
connected into the circuit.

Can you post a schematic of your circuit, please?

--
JF

Phil Allison · Aug 15, 2013

"zed wit"

"TTman"
Any simple way to dump 500Watts fixed @100 volts ? Or is it easier to
have 5 x 100R 100Watt resistors and a big heat sink ? test time would be
1minute...

light bulbs

** Why do so many fools suggest bulbs in place of resistors ??

Incandescent bulbs use tungsten wire that has a strong positive tempco - so
much so that the effective resistance value changes over a ratio of about 12
times from room temp to full brightness.

OTOH, high power resistors use wire that has almost no tempco and the same
goes for heating appliances ( jugs, toasters room heaters etc).

.... Phil

zwit · Aug 15, 2013

"TTman" <pcw1.cad@ntlworld.com> wrote in message
news:kudutp$h0t$1@dont-email.me...

Any simple way to dump 500Watts fixed @100 volts ? Or is it easier to
have 5 x 100R 100Watt resistors and a big heat sink ? test time would be
1minute...

light bulbs

Aug 15, 2013

On Wednesday, August 14, 2013 10:34:44 PM UTC-7, Jan Panteltje wrote:

On a sunny day (Wed, 14 Aug 2013 15:15:19 -0700 (PDT)) it happened

eric@bauld.com wrote in

4c4dfa6f-11f3-4679-b77e-2ac2f6b488aa@googlegroups.com>:

Here is a pic of the circuit as it stands, I added the capacitor in and it =

has stopped the green LED from starting in a indeterminate state(Sometimes =

on sometimes off). That is only if the Trip Input is open of course.

And the 100 uF cap on the power has been removed.

http://img33.imageshack.us/img33/8556/jxky.png

-----------------------------------> to gate MOSFET 1

| | |

0 || | ===

||-( reset | | 100n

0 || | ///

| |

/// |

+ | +

| | |

\ /LED | \ / LED

--- | ---

| | |

1k | 1k

|------ | |---------------> to gate MOSFET 2

c | c |

--b NPN -- b NPN |

| e e |

| | | |

| /// /// |

| |

|--------------------------

|

0 ||

||--( set

0 ||

|

///

2 transistors

In fact IIRC you do not need any semiconductors at all, can be done with relays.

I once made a MVB with one relay and a capacitor for flashing sign (for some fun thing) ....

Had to bend the contacts a bit... would not last that long.

Maybe it had a resistor too...

Try it with 2 relays only, the set-reset.

There are those pulse relays... those stay in one position, now you only need ONE relay.

Weight is important on your trip to space....

Thanks, but not sure I quite follow. Trying to relate your design with the overall design on the logic diagram.

Intention is that:
1) On power up neither relay is on
2) On momentary reset relay /w green is activated
3) If at any time trip is closed, green side is off, red is on
4) If reset is hit while trip is still open, nothing happens
5) if trip is open then reset will function and be able to trigger green led
6) At no time will both red and green be active
7) On init neither LED circuit is on

The overall circuit is not a SR Latch, it has a few required tweaks to follow the above rules.

Or were you just replacing one of the SR latches ?

Jan Panteltje · Aug 15, 2013

On a sunny day (Wed, 14 Aug 2013 15:15:19 -0700 (PDT)) it happened
eric@bauld.com wrote in
<4c4dfa6f-11f3-4679-b77e-2ac2f6b488aa@googlegroups.com>:

Here is a pic of the circuit as it stands, I added the capacitor in and it =
has stopped the green LED from starting in a indeterminate state(Sometimes =
on sometimes off). That is only if the Trip Input is open of course.
And the 100 uF cap on the power has been removed.

http://img33.imageshack.us/img33/8556/jxky.png

-----------------------------------> to gate MOSFET 1
| | |
0 || | ===
||-( reset | | 100n
0 || | ///
| |
/// |
+ | +
| | |
\ /LED | \ / LED
--- | ---
| | |
1k | 1k
|------ | |---------------> to gate MOSFET 2
c | c |
--b NPN -- b NPN |
| e e |
| | | |
| /// /// |
| |
|--------------------------
|
0 ||
||--( set
0 ||
|
///

2 transistors

In fact IIRC you do not need any semiconductors at all, can be done with relays.

I once made a MVB with one relay and a capacitor for flashing sign (for some fun thing) ....
Had to bend the contacts a bit... would not last that long.
Maybe it had a resistor too...

Try it with 2 relays only, the set-reset.

There are those pulse relays... those stay in one position, now you only need ONE relay.
Weight is important on your trip to space....

Klaus Kragelund · Aug 15, 2013

On Thursday, August 15, 2013 1:13:45 AM UTC+2, DaveC wrote:

230D1

PUICO

http://oi44.tinypic.com/33a6o89.jpg

Logo seems pretty non-descript...

Anyone recognize it?

Thanks.

Yes, I did. Se the earlier post....

Jan Panteltje · Aug 15, 2013

On a sunny day (Wed, 14 Aug 2013 23:20:29 -0700 (PDT)) it happened
eric@bauld.com wrote in
<54060329-a4b7-4627-b779-1f01858ec555@googlegroups.com>:

There are those pulse relays... those stay in one position, now you only need ONE relay.

Weight is important on your trip to space....

Thanks, but not sure I quite follow. Trying to relate your design with the overall design on the logic diagram.

Intention is that:
1) On power up neither relay is on
2) On momentary reset relay /w green is activated
3) If at any time trip is closed, green side is off, red is on
4) If reset is hit while trip is still open, nothing happens
5) if trip is open then reset will function and be able to trigger green led
6) At no time will both red and green be active
7) On init neither LED circuit is on

The overall circuit is not a SR Latch, it has a few required tweaks to follow the above rules.

Or were you just replacing one of the SR latches ?

Yes those are diffrent specs than the original SR latch you mentioned.

If it gets complicatiatered use a PIC.

It can drive the LEDs too, logic level MOSFETs, and has many more inputs for 'buttons'.
And remote conrol.. RS232
2$, internal oscillator, brownout, safe power up, etc etc, watchdog...., micro amp current....
Beat it!

Your description, logicaly speaking, is not very clear.

Aug 15, 2013

On Saturday, 9 March 2013 19:57:39 UTC, Jan Panteltje wrote:

Success:

The Raspberry Pi Spectrum Analyzer

http://panteltje.com/pub/raspberry_spectrum_analyzer.gif

This is the RTLSDR based spectrum analyzer ported to raspberry Pi,

here shown REMOTELY! via ssh -Y

So latest xforms working, and fftw3, libusb, librtlsdr, rtl_fm, etc all compiled for ARM on debian.

Soon as I get a second HDMI monitor .. as this is too big for the small

PAL monitor...

But maybe I will compile a small PAL version, after all the little monitor works great.

People interested in the source of this spectrum analyzer should ask here..

But remember, getting all libs and permission working took me a couple of hours on a Saturday..

I cheated, I changed the permissions for pi in /etc/pasword to the same as root.

Get used to it

Time is money,

I love this little computah, so far it outperforms my expectations.

Hi I'm a sound engineer, I'm interested in using a Raspberry Pi in a live environment. Having a Small 1080p display showing a Full 20Hz -> 20kHz read out taking an input from a generic USB Audio Codec device (Behringer UCA202) then showing the output on the monitor. Quick boot up time and simple display. Graph showing dB on the left with Hz along the bottom.

panfilero · Aug 15, 2013

On Wednesday, August 14, 2013 3:53:33 PM UTC-5, er...@bauld.com wrote:

On Wednesday, August 14, 2013 1:45:16 PM UTC-7, panfilero wrote:

On Wednesday, August 14, 2013 12:08:50 AM UTC-5, er...@bauld.com wrote:

I have been all over the place and cannot seem to find an actual explanation for one or many possible solutions on the race state of a SR Latch on initialization/power up

I have a small circuit on a bread board using an SR Latch, the circuit functions correctly once power is on and the SR latch has been manually used to set the desired initial state.

But, the race condition when the circuit is powered is very indeterminate and it bounces back and forth to which state wins. But I cannot seem to find an explanation as to how to set the initial state properly and then have it function as normal.

I have tried a few methods on my own but none seem reliable enough. Am I missing something as it seems like it should be quite simple, but I have not seen a solution I can apply on my board. Either I'm blind and its right in front of my face or somehow I have been unable to Google it. Found a LOT of sites explaining the race condition, but no solutions on how to "set" it.

-E

Assuming it has an Active Low reset pin, could you tie its Reset to ground through a large cap and series resistor, that way when you boot up the reset pin will be held low until the cap charges up enough to decouple the reset pin from ground?

There is no reset pin I am aware of, the SR Latch is constructed from two NOR gates on a quad input NOR gate IC.

If the latch was fully embedded into a IC instead of constructed from two NOR gates.. not sure I understand how the reset works in that case. Do you know of a chip that has that functionality? Just so I can see it and try to figure out how that relates to what was previously brought up.

-E

The SR latch has 2 inputs S = Set and R = Reset. You can make it out of two NOR gates or two NAND gates, if you make it out of NOR gates then you must hold your reset pin high until your chip boots up, if you make it out of NAND gates you hold your reset low until your chip boots up. Holding the reset pin in this way until your chip powers up could help you always boot up into the same state.

Tom Del Rosso · Aug 15, 2013

Robert Baer wrote:

"Porter is dead right, unfortunately, on not giving any information to
the police without talking to counsel first. Having been a cop in one
of the highest crime districts in the US, and then moving on to
'policing the police' as an Internal Affairs detective, I've seen
ubiquitous abuse of power which continue to escalate.

Look at the incredible behavior of NASA seizing moon rock samples that
astronauts gave as gifts. They get an old lady with a rock to come forward
and then swarm her in riot gear. They all swear to defend the Constitution
but don't understand what that means.

--

Reply in group, but if emailing remove the last word.

Aug 15, 2013

On Wednesday, August 14, 2013 11:49:30 PM UTC-7, Jan Panteltje wrote:

On a sunny day (Wed, 14 Aug 2013 23:20:29 -0700 (PDT)) it happened

eric@bauld.com wrote in

54060329-a4b7-4627-b779-1f01858ec555@googlegroups.com>:

There are those pulse relays... those stay in one position, now you only need ONE relay.

Weight is important on your trip to space....

Thanks, but not sure I quite follow. Trying to relate your design with the overall design on the logic diagram.

Intention is that:

1) On power up neither relay is on

2) On momentary reset relay /w green is activated

3) If at any time trip is closed, green side is off, red is on

4) If reset is hit while trip is still open, nothing happens

5) if trip is open then reset will function and be able to trigger green led

6) At no time will both red and green be active

7) On init neither LED circuit is on

The overall circuit is not a SR Latch, it has a few required tweaks to follow the above rules.

Or were you just replacing one of the SR latches ?

Yes those are diffrent specs than the original SR latch you mentioned.

If it gets complicatiatered use a PIC.

It can drive the LEDs too, logic level MOSFETs, and has many more inputs for 'buttons'.

And remote conrol.. RS232

2$, internal oscillator, brownout, safe power up, etc etc, watchdog...., micro amp current....

Beat it!

Your description, logicaly speaking, is not very clear.

Had link to a pic of what I currently have, and the capacitor change. It must have been missed though.
Here is the link to the current logic I am working with on a bread board.

http://img33.imageshack.us/img33/8556/jxky.png

Aug 15, 2013

On Thursday, August 15, 2013 7:58:15 AM UTC-7, panfilero wrote:

On Wednesday, August 14, 2013 3:53:33 PM UTC-5, er...@bauld.com wrote:

On Wednesday, August 14, 2013 1:45:16 PM UTC-7, panfilero wrote:

On Wednesday, August 14, 2013 12:08:50 AM UTC-5, er...@bauld.com wrote:

I have been all over the place and cannot seem to find an actual explanation for one or many possible solutions on the race state of a SR Latch on initialization/power up

I have a small circuit on a bread board using an SR Latch, the circuit functions correctly once power is on and the SR latch has been manually used to set the desired initial state.

But, the race condition when the circuit is powered is very indeterminate and it bounces back and forth to which state wins. But I cannot seem to find an explanation as to how to set the initial state properly and then have it function as normal.

I have tried a few methods on my own but none seem reliable enough. Am I missing something as it seems like it should be quite simple, but I have not seen a solution I can apply on my board. Either I'm blind and its right in front of my face or somehow I have been unable to Google it. Found a LOT of sites explaining the race condition, but no solutions on how to "set" it.

-E

Assuming it has an Active Low reset pin, could you tie its Reset to ground through a large cap and series resistor, that way when you boot up the reset pin will be held low until the cap charges up enough to decouple the reset pin from ground?

There is no reset pin I am aware of, the SR Latch is constructed from two NOR gates on a quad input NOR gate IC.

If the latch was fully embedded into a IC instead of constructed from two NOR gates.. not sure I understand how the reset works in that case. Do you know of a chip that has that functionality? Just so I can see it and try to figure out how that relates to what was previously brought up.

-E

The SR latch has 2 inputs S = Set and R = Reset. You can make it out of two NOR gates or two NAND gates, if you make it out of NOR gates then you must hold your reset pin high until your chip boots up, if you make it out of NAND gates you hold your reset low until your chip boots up. Holding the reset pin in this way until your chip powers up could help you always boot up into the same state.

I used a capacitor to slow down one of the paths returning from one nor gate to the input on the other.
Would one use a delayed transistor to hold the reset pin on the latch to achieve what you are mentioning?

Jan Panteltje · Aug 15, 2013

On a sunny day (Thu, 15 Aug 2013 05:40:49 -0700 (PDT)) it happened
jedilego@gmail.com wrote in
<42581ec5-6bf8-4861-956f-15ecb2f62ee3@googlegroups.com>:

I love this little computah, so far it outperforms my expectations.

Hi I'm a sound engineer, I'm interested in using a Raspberry Pi in a live e=
nvironment. Having a Small 1080p display showing a Full 20Hz -> 20kHz read =
out taking an input from a generic USB Audio Codec device (Behringer UCA202=
) then showing the output on the monitor. Quick boot up time and simple dis=
play. Graph showing dB on the left with Hz along the bottom.

Seems like you have to do some programming,
but do not things like 'audacity' have a FFT display?

I wrote xpequ:
http://panteltje.com/panteltje/xpequ/index.html

should compile on the Pi too, has simple scope and FFT.

Also graphic equalizer... AGC, whatever...

There is also a simple program (very simple) called 'xspectrum' that should work on the Pi,
if you can get that sound thing recognised...

I was trying to get a cheap Easycap USB device fro mebay working on the Pi,
no luck so far, it has video and audio.
Maybe the audio works, seems others cannot get teh video to work either,
works on the PC though.

Does the Pi recognize the UCA202?

Uwe Hercksen · Aug 15, 2013

Phil Allison schrieb:

** Why do so many fools suggest bulbs in place of resistors ??

Incandescent bulbs use tungsten wire that has a strong positive tempco - so
much so that the effective resistance value changes over a ratio of about 12
times from room temp to full brightness.

Hello,

the fools are not aware of the dramatic change of resistance between a
cold and hot bulb...

Bye

Aug 15, 2013

On Thursday, August 15, 2013 12:46:27 PM UTC-4, er...@bauld.com wrote:

http://img33.imageshack.us/img33/8556/jxky.png

That's ridiculous. The gates don't come close to satisfying:
"Intention is that:
1) On power up neither relay is on
2) On momentary reset relay /w green is activated
3) If at any time trip is closed, green side is off, red is on
4) If reset is hit while trip is still open, nothing happens
5) if trip is open then reset will function and be able to trigger green led
6) At no time will both red and green be active
7) On init neither LED circuit is on "

The most basic logic is wrong. Maybe think about a less challenging project.

Fred Bartoli · Aug 15, 2013

Le Thu, 15 Aug 2013 07:58:15 -0700, panfilero a ĂŠcrit:

On Wednesday, August 14, 2013 3:53:33 PM UTC-5, er...@bauld.com wrote:
On Wednesday, August 14, 2013 1:45:16 PM UTC-7, panfilero wrote:

On Wednesday, August 14, 2013 12:08:50 AM UTC-5, er...@bauld.com
wrote:

I have been all over the place and cannot seem to find an actual
explanation for one or many possible solutions on the race state of
a SR Latch on initialization/power up

I have a small circuit on a bread board using an SR Latch, the
circuit functions correctly once power is on and the SR latch has
been manually used to set the desired initial state.

But, the race condition when the circuit is powered is very
indeterminate and it bounces back and forth to which state wins.
But I cannot seem to find an explanation as to how to set the
initial state properly and then have it function as normal.

I have tried a few methods on my own but none seem reliable enough.
Am I missing something as it seems like it should be quite simple,
but I have not seen a solution I can apply on my board. Either I'm
blind and its right in front of my face or somehow I have been
unable to Google it. Found a LOT of sites explaining the race
condition, but no solutions on how to "set" it.

-E

Assuming it has an Active Low reset pin, could you tie its Reset to
ground through a large cap and series resistor, that way when you
boot up the reset pin will be held low until the cap charges up
enough to decouple the reset pin from ground?

There is no reset pin I am aware of, the SR Latch is constructed from
two NOR gates on a quad input NOR gate IC.

If the latch was fully embedded into a IC instead of constructed from
two NOR gates.. not sure I understand how the reset works in that case.
Do you know of a chip that has that functionality? Just so I can see it
and try to figure out how that relates to what was previously brought
up.

-E

The SR latch has 2 inputs S = Set and R = Reset. You can make it out of
two NOR gates or two NAND gates, if you make it out of NOR gates then
you must hold your reset pin high until your chip boots up, if you make
it out of NAND gates you hold your reset low until your chip boots up.
Holding the reset pin in this way until your chip powers up could help
you always boot up into the same state.

If building from discrete gates, just use 3 input NAND or NOR gates, as
needed. Use 2 inputs as usual, then one left one as reset input and the
other left one tied to VCC/GND, depending on which gate you used.

--
Thanks,
Fred.

Aug 15, 2013

On Thursday, August 15, 2013 11:23:38 AM UTC-7, bloggs.fred...@gmail.com wrote:

On Thursday, August 15, 2013 12:46:27 PM UTC-4, er...@bauld.com wrote:

http://img33.imageshack.us/img33/8556/jxky.png

That's ridiculous. The gates don't come close to satisfying:

"Intention is that:

1) On power up neither relay is on

2) On momentary reset relay /w green is activated

3) If at any time trip is closed, green side is off, red is on

4) If reset is hit while trip is still open, nothing happens

5) if trip is open then reset will function and be able to trigger green led

6) At no time will both red and green be active

7) On init neither LED circuit is on "

The most basic logic is wrong. Maybe think about a less challenging project.

Perhaps something is lost in translation. As I have it placed out on a bread board and it is functioning as required. The only change I had to make was the capacitor which as far as I could tell set the initial state of the SR Latch to avoid the race condition.

Phil Allison · Aug 16, 2013

"Uwe Hercksen"

Phil Allison schrieb:

** Why do so many fools suggest bulbs in place of resistors ??

Incandescent bulbs use tungsten wire that has a strong positive tempco -
so much so that the effective resistance value changes over a ratio of
about 12 times from room temp to full brightness.

Hello,

the fools are not aware of the dramatic change of resistance between a
cold and hot bulb...

** They should measure the resistance of a cold bulb some time....

.... Phil

Jan Panteltje · Aug 16, 2013

On a sunny day (Thu, 15 Aug 2013 09:46:27 -0700 (PDT)) it happened
eric@bauld.com wrote in
<42338cb8-2e4d-43a8-8c8d-c99c4480baca@googlegroups.com>:

Your description, logicaly speaking, is not very clear.

Had link to a pic of what I currently have, and the capacitor change. It must have been missed though.
Here is the link to the current logic I am working with on a bread board.

http://img33.imageshack.us/img33/8556/jxky.png

Yes I have seen that, but was referring to your text.
About the same for the circuit diagram though.

Driver to drive?

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