Replace Batteries with DC Power Supply

I have some fairy lights used to light up some lanterns at home.

The lights are battery powered. I’m using rechargeable batteries but it’s still a hassle replace the batteries when they die. I decided to replace the batteries with a DC power supply which I can just plug in to an ordinary electrical outlet. I could then use a smart outlet to programmatically turn on the lights whenever I want.

To convert the batteries to use a DC power supply, here’s what I did.

  • Since the lights take 3 AA (1.5V) batteries, the total voltage I need the DC power supply to provide is 4.5 V. I an AC (120V) to DC (5V) power supply on Amazon with barrel to wire connector adapter for $9.
  • 1/2″ diameter round wood dowel from Home Depot (3 ft for ~ $3)
  • Speaker wire

I cut the wood dowel to the length of a AA battery. Drill a hole in one end. Partially screwed in a screw. Stripped the end off of a bit of speaker wire. Wound up the end of the wire around screw and screwed the screw in.

I then identified the positive and negative terminals in the battery pack and inserted my fake batteries in them. The wires from each fake battery were then connected to the corresponding positive and negative terminals to the DC power supply. Everything works.

Circuit Breakers, Electrical Wiring and Device Wattage

I need to install an electric fireplace but I’m not sure if the circuit can handle the load with other devices on. Here’s an explanation of device load, electrical wiring and circuit breakers.

In a typical residential home, you’ll have two types of circuits:

  • 15A (amp) circuit using 14 gauge (thin) electrical wire (usually white) connected to a 15A circuit breaker. Based on the formula P (watt) = V (volts) x i (current), the max wattage this circuit can handle before tripping the circuit breaker is 120 V x 15 A = 1800 W. This circuit is usually used for general lighting.
  • 20A (amp) circuit using 12 gauge (thick) electrical wire (usually yellow) connected to a 20A circuit breaker. This circuit can support a total load of 120V x 20A = 2400 W. This circuit is usually used for kitchen devices.

You can’t just replace a 15A circuit breaker with a 20A one since the wires going into the 15A circuit breaker are likely 14 gauge (thin) wires. If these wires carry a load greater than 1500 watts, the wire can burn, catch on fire, and burn the house down. When installing new circuits, just always use 12 gauge wiring even if connected to a 15 amp circuit breakers.

In the example above, I have these devices

  • electric fireplace (1500 W)
  • LG OLED 65″ TV (150 W)
  • 2 x LED lamps (2 x 15 W = 30 W)

Total power consumption = 1500 W + 150 W + 30 W = 1680 W. Since this is less than 1800 W (the max wattage for a 15 A circuit), I should be okay, although it would be preferable to put the fireplace on a 20A circuit.

How to Build a Strong, Attractive Good-Neighbor Fence

Goals:

  • No gaps between boards
  • Strong, sturdy
  • Inexpensive
  • Looks good on both sides
  • Simple to build
  • Long-lasting

Materials

Wood Post or Steel Post:

Many people use pressure-treated wood posts but though they are cheaper, they do have downsides includng:

  • they can rot and decay
  • they can warp and bend, especially if you leave them out in the sun and don’t finish the fence right away
  • attaching 2x4s to them require toenailing or toescewing nails and screws at an angle or using metal brackets for 2x4s
  • if you attach 2x4s to the post and later decide you want to move them up or down, it’s a hassle

Steel posts have holes all along the length on both sides so screwing 2x4s into them are very easy. This saves a lot of time and money from not having to buy a bunch of brackets. Furthermore, there’s no worry about it warping due to the elements.

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Creating House Floor Plans in 2D and 3D

If you need to only create 2d house floor plans, I personally have found Lucidchart to be easy to learn and intuitive to use.

If you need to create 3d house floor plans, I have found Live Home 3D to offer the best features for the price. At $10 (on sale), you can easily create 2d and 3d home plans. You download and install the program which allows for faster 3d rendering. My typical workflow to design a house is as follows:

1. Create a room by clicking the Room button

2. Draw a room (2d) by dragging the shape of a rectangle

3. Pick a door style

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Easily Tighten a Rope Without a Knot

When you need to tighten a rope to hold something in place, e.g. a tent, cargo in a pickup truck, a leaning tree, bed sheets, etc, you might think you’ll need to tie a knot. Not only is it difficult to tie a knot without losing tension in the rope, it’s a hassle and often difficult untying the knot. Ratchet straps are easier to use but are overkill for non-heavy duty situations. A simpler solution is to use a figure 9.

Here, I used a figure 9 to hold a leaning tree in place.

You can purchase Figure 9s at REI. One brand is Nite-ize but there’s also generic ones on Amazon for less.

This are two ways to tighten a rope using a Figure 9.

How to Finish Wood With a Protective Coat

I recently worked on a project to replace my stair’s handrails. I bought the unfinished handrails at Home Depot and then stained them easily as follows.

Applying Wood Stain

  1. Using a brush, applied one coat of Minwax Pre-stain Conditioner
  2. Using a brush, applied one coat Minwax Stain (Gunstock color). While the stain was wet, I wiped it with a paper towel to prevent some areas to be thicker or darker than others. Though wiping with a towel lightens the stain, it is an important step. To achieve darker stains, just repeat the staining and wiping process.

Note: Applying anything wet, e.g. stain, to wood will cause the grain to rise resulting in bumps. If, after the first coat of stain, you notice bumpiness, then sand it down with 220 grit sandpaper until the bumps are gone and then restain the wood. This first coat following by the sanding process serves as a sort of “primer” to prepare the surface.

The tricky part was getting the protective finish coat on. I wanted a shiny, smooth, glossy handrail. After trying different products and processes, here’s my advice.

Lacquer vs Polyurethane

Lacquer is sticky and seemingly more toxic. My eyes felt weird even though none of it gone in them. A bit of lacquer got on my hands and cleaning my hands were a hassle and temporarily messed up my skin. The fumes were so strong I could smell some of it in other rooms of my house. Cleaning the brush used to apply the lacquer was impossible so it had to be thrown away.

Polyurethane is also toxic but the water based kind is easy to clean by simply rinsing with water and it doesn’t smell as much. I was able to easily rinse my brush so I could reuse it for additional coats.

Conclusion: Don’t even bother with lacquer. Just stick with polyurethane.

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How to Enlarge a Hole in a Wall

The other day I was drilling a hole in a wall to run a 3-prong extension cord through. I thought a 1 inch spade bit would do to create 1 inch diameter hole. Unfortunately, the plug end of the cord was still too big to fit through the hole. I couldn’t enlarge the hole using a hole saw bit

because that requires some material for the center shaft to bite in to. 

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