I have bought one of those cheap Hakko handles (price around $15), a few T12 tips and a $10 hakko controller for evaluation purposes from eBay. The handle requires 12V ... 24V DC power supply, and I am running it at 24VDC for the best performance.
Kalvin is there a thread on this already? or would you care to create one with the parts you used and what you found during assembly etc?
Here is my hobby soldering station parts list:
1. Soldering Iron Controller $8 - $10 :
- Enter magic keywords to Ebay: Hakko T12
- You can buy a controller with a handle if you wish. I opted to buy a separate handle.
- The controller may need some parameter adjustment for the best temperature control and accuracy.
2. Soldering Iron Handle $15 - $20:
- Enter magic keywords to Ebay: T12 soldering iron
- Select a handle for the 70W T12 soldering tips
3. DC-DC Converter 150W $4 - $8:
- Enter magic keywords to Ebay: dc-dc 150W
- This is optional if you have a power supply 20V - 24V / 4A.
- Has an on-board fuse
- Input voltage can be 12V - 20V DC
- Output voltage will be adjusted to 24V / 70W
- The peak input current from the power supply will be 5 - 6 Amperes at 12V, 2 -3 Amperes on average
- With a DC-DC-boost converter the soldering iron can be used with any input voltage between 12V - 20V giving 24V 70W
- Doesn't generate lot of heat, so it can be placed inside the enclosure
- The cheap DC-DC-converter may produce some audible high pitch noise at lower input voltage levels.
4. Enclosure for the controller and the DC-DC-converter $14:
- Enter magic keywords to Ebay: T12 soldering iron case
- I do not have access to proper tools, so I went and bought a ready-made enclosure
- Modified the backpanel for a DC plugin power connector
- The DC-DC converter is mounted inside the enclosure
- The minus power of the DC-DC converter is connected to the enclosure through a 1 megaohm resistor
- The enclosure is connected to the ESD ground through a 1 megaohm resistor
5. Buy a selection of T12 tips
- These T12-type tips are available from Ebay for decent price
- I do not know yet how well they perform or how long they will last, but they are cheap and fast to change
6. Power supply
- Use any safe power supply giving output power of 70W: 12V@6A - 24V@3A
- Some switching mode power supplies have quite high leakage current which may be a problem without a proper grounding and ESD protection
- I would consider the [chinese] switching power supplies using the mains voltage
UNSAFE that are sold with some of the T12 soldering iron kits with the aluminium enclosure
I have tested this configuration successfully with a lab power supply, done basic measurements, monitored for any heating problems and done basic soldering job. At this point I am very happy with the purchases. Now I have a fairly inexpensive, fast iron with a temperature control suitable for a SMD work with a good selection of different tips that can be changed in seconds.
I am still in the process of getting a proper power supply. The target is to find a switched mode 90W - 120W laptop power supply with very low leakage current. The other option is to purchase a 100W medical grade transformer with output voltage in range of 12 V - 24V which should provide only very little leakage current.
In summary: This is one possible option to get a nice hobby soldering iron station with a decent performance in $30 - $50 price range. If you have the tools for building a nice enclosure and already have a suitable power supply, you can get the described soldering iron station for $30 or less. With the (optional) DC-DC-converter the soldering station can be powered from the 12V car battery if needed and still get the 70W heating performance.
Disclaimer: I have not tested the controller and the DC-DC-converter thoroughly in long term use, so please keep in mind that there may be some possible problems that I haven't discovered yet. Also, I do not know how well the controller behaves or what happens if it fails to "always on"-state powering the handle with a constant voltage of 24V. Please consider adding a timer relay which will power off the soldering station after specified time period.