Sunday, March 19, 2017

Coffee maker PID Temperature Control

My name is RP  i'm working on a project to regulated the temperature of a coffee maker. I don''t know were to start. what i want is to regulate the temperature of the coffee. Could you please help me.

Mail from RP

This is what you may have to do. study below pages and try.

Murph's Silvia PID Page - This page describes my effort to improve temperature control in a home espresso machine by installing a PID temperature controller. If you are reading this page, then you probably already know what Silvia is, what PID means and why anyone would want to add one to the other.

Coffee maker PID Temperature Control

Tuning a PID (Three-Mode) Controller - . If the controller does not include an autotune algorithm or the autotune algorithm does not provide adequate control for the particular application, the unit must then be tuned using a trial and error method.

PID controller - Wikipedia - A PID controller continuously calculates an error value {\displaystyle e(t)} e(t) as the difference between a desired setpoint and a measured process variable and applies a correction based on proportional, integral, and derivative terms.

Temperature Control - PID and LabVIEW - First, let's take a look at how the PID controller works in a closed-loop system using the schematic shown above. The variable (e) represents the tracking error, the difference between the desired input value (R) and the actual output (T). This error signal (e) is sent to the PID controller.


Saturday, March 18, 2017

Halogen bulb lamp dimmer circuit

Can someone provide me a (simple) schematic for a dimmer that would control 12 VAC about 80 watts. This would be used to control a lamp with halogen bulbs.

A comment in Hobby Hound

Here is a listing study them and choose, try out, learn and then build the one right for you.

1200 Watt Lamp Dimmer Circuit The following circuit is a lamp dimmer circuit that is capable of controlling up to 1200 Watts. The circuit uses the Q4015LT combination Diac and Triac that is available from Digikey Electronics.

PWM Motor Speed Controller / DC Light Dimmer - Here is a listing study them and choose, try out, learn and then build the one right for you.

DC Controlled Dimmer Velleman kit - K8064

Halogen bulb lamp dimmer circuit

Simple brightness adjustment by means of a DC voltage, optically isolated adjustment input. Pre-set adjustment for full brightness, suitable for incandescent lamps, mains voltage halogen lighting and low voltage halogen lighting in combination with a conventional transformer. "Soft start" feature to ensure lamp longevity, transformer protection in case of defective light sources

Electronic Transformer for 12V Halogen Lamp - STMicro
The topology of the circuit is the classic half-bridge. The control circuit could be realised using an IC (so fixing the operating frequency), but there is a more economical solution which consists of a selfoscillating circuit where the two transistors are driven in opposing phase by feedback from the output circuit.


Friday, March 17, 2017

How to Connect RTD to transmitter

Can you explain me were i have to conect the three cables of the PT100 in the Circuit RTD-Pt-100-Transmitter Circuit?

RTD PT100 Transmitter and Multiplexer

Comment from CV of Spain

You have a three wire RTD, there is also a 4 wire RTD type, This circuit can be used for both.

In the 3W RTD you have two wires coming from the same point (zero ohms between them) the third wire will be 100 ohms from these two. From the two wires that are at same point take one wire and give 1mA from Q3 + OUT. The other wire of the pair connect to input +..... input - can be connected to the 100E end.

How to Connect RTD to transmitter

So imagine that I have three wires one white and two blacks.

One black to +OUT 1ma
Other black to input-

And waht about the withe one that is the one that give me arround 100ohms??

Reply from CV

Black 1 - +Out 1mA
Black 2 - +Input
White goes to -Input

See NI Developer Zone - RTD Connections