Search found 386 matches

by markaren1
Mon Sep 18, 2017 1:48 pm
Forum: Projects
Topic: General arrangement 2 x 10w RGB controller (12v)
Replies: 1
Views: 312

Re: General arrangement 2 x 10w RGB controller (12v)

Can you put up a schematic of your ideas please, the description is ambiguous (at least to me).

Also, why not control brightness directly using PWM, it looks like the AL8805 (on the picobuck) could accept a 3V3 control signal directly from an Arduino...

-Mark
by markaren1
Sat Sep 16, 2017 8:53 pm
Forum: Projects
Topic: Touch Screen Relay Controller
Replies: 3
Views: 564

Re: Touch Screen Relay Controller

You can easily monitor multiple inputs and control multiple outputs from a single-threaded CPU. From you requirements, how about using a smart-phone connected (by WiFi) to an ESP-8266 which is the web-server, and is also doing the heavy(!) lifting. Have a look at micro-python for that target. -Mark
by markaren1
Sat Sep 09, 2017 12:45 pm
Forum: Projects
Topic: Which battery to use in my project for long autonomy
Replies: 3
Views: 701

Re: Which battery to use in my project for long autonomy

That should read "You will probably also need to learn about the evils of back-powering (ex: driving current from a powered/active CPU into an unpowered peripheral".

-Mark
by markaren1
Fri Sep 08, 2017 10:25 pm
Forum: Projects
Topic: Which battery to use in my project for long autonomy
Replies: 3
Views: 701

Re: Which battery to use in my project for long autonomy

Starting point is to get some kind of a power budget before you need to worry about 'how big the battery is'. Unless the peripherals can be put into a really low power mode, you may have to have switched power for the hc-sr04 and the WiFi module. To save power, the peripherals should only be enabled...
by markaren1
Fri Sep 08, 2017 5:48 pm
Forum: Projects
Topic: Problem with proceeding circuit on a power suply. Can help?
Replies: 9
Views: 856

Re: Problem with proceeding circuit on a power suply. Can he

A half-reasonable schematic would be useful, please post one.
by markaren1
Wed Sep 06, 2017 12:09 pm
Forum: Projects
Topic: wierless audio
Replies: 1
Views: 335

Re: wierless audio

Can you post a link to the commercial product that you mention please.

-Mark
by markaren1
Wed Sep 06, 2017 2:58 am
Forum: Projects
Topic: arduino mega to nano
Replies: 2
Views: 500

Re: arduino mega to nano

You are completely recompiling for the new target hardware aren't you ?

and not just trying to program the nano using the same object file you created for the mega...

Also, have you successfully compiled and programmed the nano with some trivial code (blinky etc).

-Mark
by markaren1
Tue Sep 05, 2017 5:12 pm
Forum: Projects
Topic: triggering my Triac...
Replies: 4
Views: 799

Re: triggering my Triac...

I tend to agree with darrellg's suggestion as a safe approach to the problem. Opto-TRIACs have their place, but only if the all-encompassing issue of electrical safety is fully understood first, and the OP appears to be new to this whole arena.

-mark
by markaren1
Tue Sep 05, 2017 11:48 am
Forum: Projects
Topic: Generate 70MHz signal with 5 voltage levels
Replies: 1
Views: 568

Re: Generate 70MHz signal with 5 voltage levels

Have a look at the terASIC DE0-nano; complete, and low cost FPGA dev board.

Multi-level high speed stuff; might want to use an 8 bit DAC running at 200MSPS to synthesize a 70MHz signal, you will then have plenty of flexibility for design changes.

-Mark
by markaren1
Tue Sep 05, 2017 11:41 am
Forum: Projects
Topic: Polyurethane as a conformal coating.
Replies: 4
Views: 736

Re: Polyurethane as a conformal coating.

From http://4hv.org/e107_files/public/1490831097_61521_FT179355_dielectric_strength_of_insulating_materials_-crc_handbook_of_chemistry__physics_.pdf ... it looks like polyurethane has around 50 times the electric breakdown strength of air, so even a thin coating will be useful in your application. A...
by markaren1
Tue Sep 05, 2017 11:31 am
Forum: Projects
Topic: triggering my Triac...
Replies: 4
Views: 799

Re: triggering my Triac...

Hello webwiz355, Sounds like you are using live mains with this project. Can I respectfully suggest that you fully read up on safety before you go any further. IMHO you need to fully understand the dangers of the situation, and how to manage them before you worry about blowing up TRIACs. While not c...
by markaren1
Tue Mar 22, 2016 8:34 pm
Forum: Projects
Topic: Servo Potentiometer Issue
Replies: 9
Views: 652

Re: Servo Potentiometer Issue

Try swapping the end wires to the pot, it night be wired electrically/mechanically backwards

-Mark
by markaren1
Mon Mar 30, 2015 10:41 am
Forum: Projects
Topic: PWM pull up or pull down
Replies: 2
Views: 396

Re: PWM pull up or pull down

Pull ups or pull downs are not just associated with PWM, they form part of the topology of an output driver circuit. Generally, digital outputs are formed by a current sink (usually to gnd), and a current source (usually to supply). Yes, if the output is open collector, or open drain, a pull up of o...
by markaren1
Sun Jul 06, 2014 5:42 pm
Forum: Projects
Topic: High-torque servo and small movements?
Replies: 6
Views: 600

Re: High-torque servo and small movements?

Yes, a stepper sounds like a much easier solution.

Make sure that you are operating the motor well below the torque required for the rotor to slip.

-mark
by markaren1
Tue Jul 01, 2014 8:56 pm
Forum: Projects
Topic: Two-Wire H-Bridge
Replies: 11
Views: 1436

Re: Two-Wire H-Bridge

Assume you are driving the circuit made of transistors above. Connect a logic inverter between fwd and rev inputs, with the input on fwd. On the fwd input, now apply a PWM waveform maybe 1kHz. With the PWM set to 50:50, the average difference between the motor terminals is 0v, so it is stationary. S...