2018-07-10 10:44:59 +02:00
|
|
|
---
|
|
|
|
|
title: "Saike 858D++ - First Block Diagram"
|
2018-07-10 10:51:09 +02:00
|
|
|
date: 2018-07-10T10:45:00+02:00
|
2018-07-10 10:44:59 +02:00
|
|
|
author: eNBeWe
|
|
|
|
|
type: post
|
|
|
|
|
categories:
|
|
|
|
|
- Allgemein
|
|
|
|
|
- Bastelkram
|
|
|
|
|
tags:
|
|
|
|
|
- 858D
|
|
|
|
|
- DIY
|
|
|
|
|
- Arduino
|
|
|
|
|
---
|
|
|
|
|
|
|
|
|
|
After a short break, here is the first part about the redesign of the Saike 858D rework station ([Overview][1]).
|
|
|
|
|
|
|
|
|
|
Let's talk about a rough block diagram for the new design.
|
|
|
|
|
|
|
|
|
|
<!--more-->
|
|
|
|
|
|
|
|
|
|
[](/posts/images/858D/Concept-New-Design_V1-big.png)
|
|
|
|
|
|
|
|
|
|
Let's have a look at the general structure and first follow the path of the power supplies.
|
|
|
|
|
Twe build a mains powered device so we start with that at the top left.
|
|
|
|
|
The mains power is fed into the heater control circuit as well as a 24V switch mode power supply,
|
|
|
|
|
which I will use to replace the transformer.
|
|
|
|
|
|
|
|
|
|
The 24V power supply is connected to the fan control circuit and another switch mode supply,
|
|
|
|
|
this time providing a 5V rail.
|
|
|
|
|
The 5V supply is used for an Arduino board,
|
|
|
|
|
which will be plugged on the main PCB. I have not yet decided which model I want to use,
|
|
|
|
|
but it will probably be one of the Pro Micro or Nano boards I have lying around.
|
|
|
|
|
Additionally, the 5V supply is used for the other logic level components,
|
|
|
|
|
like the display and the sensors.
|
|
|
|
|
|
|
|
|
|
The Arduino is connected to the heater and fan control circuits,
|
|
|
|
|
both regulated through some form of PWM.
|
|
|
|
|
The heater control will use more or less the same design as the original,
|
|
|
|
|
regulating the heater through a optocoupled triac.
|
|
|
|
|
The fan control will use regular PWM to switch a power mosfet that
|
|
|
|
|
can in turn regulate the fan supply.
|
|
|
|
|
Additionally, there will be a form of monitoring of the fan speed.
|
|
|
|
|
I am currently pondering which way I want to go there.
|
|
|
|
|
|
|
|
|
|
The display will be replaced by two 7-segment displays with 4 digits each.
|
|
|
|
|
The displays are controlled by a MAX7219 IC,
|
|
|
|
|
which is connected to the Arduino through SPI.
|
|
|
|
|
|
|
|
|
|
The sensor inputs from the handle sensor and the thermocouple
|
|
|
|
|
are fed into the Arduino directly and are used in the control loop.
|
|
|
|
|
|
|
|
|
|
That's about it. There is still some uncertainty about some desin points,
|
|
|
|
|
but I am feeling confident that this should, at least roughly, work.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
[1]: {{<relref "2018-06-20-Reverse-Engineer-a-Saike-858D.md">}}
|
|
|
|
|
|
